move(): Give compiler an opportunity to optimize

Fix #75.

.gitignore

@@ -10,7 +10,7 @@ dub.selections.json
 __test__*__
 __test__*__.core
 /tanya-test-*
-/dub_platform_probe-*
+/dub_platform_probe[_-]*
 
 /docs/
 /docs.json

.travis.yml

@@ -1,39 +1,61 @@
 sudo: false
 
 os:
-  - linux
-  - osx
+- linux
+- osx
 
 language: d
 
 d:
-  - dmd-2.080.0
-  - dmd-2.079.1
-  - dmd-2.078.3
-  - dmd-2.077.1
+- dmd-2.083.1
+- dmd-2.082.1
 
 env:
+  global:
+  - LATEST=2.083.1
+
   matrix:
-    - ARCH=x86_64
-    - ARCH=x86
+  - ARCH=x86_64
+  - ARCH=x86
+
+matrix:
+  include:
+  - name: D-Scanner
+    d: dmd-$LATEST
+    env: DSCANNER=0.5.11
+    os: linux
+  - name: DDoc
+    d: dmd-$LATEST
+    env: DDOC=true
+    os: linux
+  allow_failures:
+  - name: D-Scanner
+    d: dmd-$LATEST
+    env: DSCANNER=0.5.11
+    os: linux
 
 addons:
   apt:
     packages:
-      - gcc-multilib
+    - gcc-multilib
 
 before_script:
-  - if [ "`$DC --version | head -n 1 | grep 'v2.080.0'`" ]; then
-      export UNITTEST="unittest-cov";
-    fi
+- if [ "`$DC --version | head -n 1 | grep v$LATEST`" ] &&
+     [ -z "$DSCANNER$DDOC" ]; then
+    export UNITTEST="unittest-cov";
+  fi
 
 script:
-  - dub test -b ${UNITTEST:-unittest} --arch=$ARCH --compiler=$DC
-  - if [ "$UNITTEST" ] && [ "$ARCH" = "x86_64" ] && [ "$TRAVIS_OS_NAME" = "linux" ];
-    then
-      dub fetch dscanner;
-      dub run dscanner -- --styleCheck ./source/;
-    fi
+- if [ -n "$DDOC" ]; then
+    dub build -b ddox --compiler=$DC;
+  elif [ -z "$DSCANNER" ]; then
+    dub test -b ${UNITTEST:-unittest} --arch=$ARCH --compiler=$DC;
+  else
+    dub fetch dscanner --version=$DSCANNER;
+
+    FILES=$(find source -type f);
+    dub run dscanner -- --styleCheck $FILES;
+  fi
 
 after_success:
-  - test "$UNITTEST" && bash <(curl -s https://codecov.io/bash)
+- test "$UNITTEST" && bash <(curl -s https://codecov.io/bash)

README.md

@@ -25,6 +25,7 @@ Tanya consists of the following packages and (top-level) modules:
 
 * `algorithm`: Collection of generic algorithms.
 * `async`: Event loop (epoll, kqueue and IOCP).
+* `bitmanip`: Bit manipulation.
 * `container`: Queue, Array, Singly and doubly linked lists, Buffers, UTF-8
 string, Set, Hash table.
 * `conv`: This module provides functions for converting between different
@@ -32,6 +33,8 @@ types.
 * `encoding`: This package provides tools to work with text encodings.
 * `exception`: Common exceptions and errors.
 * `format`: Formatting and conversion functions.
+* `functional`: Functions that manipulate other functions and their argument
+lists.
 * `hash`: Hash algorithms.
 * `math`: Arbitrary precision integer and a set of functions.
 * `memory`: Tools for manual memory management (allocators, smart pointers).
@@ -170,12 +173,10 @@ parameter is used)
 
 ### Supported compilers
 
-| DMD     | GCC       |
-|:-------:|:---------:|
-| 2.080.0 | *master*  |
-| 2.079.1 |           |
-| 2.078.3 |           |
-| 2.077.1 |           |
+| DMD     | GCC             |
+|:-------:|:---------------:|
+| 2.083.1 | gdc-8 (2.081.2) |
+| 2.082.1 | gdc-7 (2.081.2) |
 
 ### Release management
 

appveyor.yml

@@ -4,28 +4,16 @@ os: Visual Studio 2015
 environment:
   matrix:
     - DC: dmd
-      DVersion: 2.080.0
+      DVersion: 2.083.1
       arch: x64
     - DC: dmd
-      DVersion: 2.080.0
+      DVersion: 2.083.1
       arch: x86
     - DC: dmd
-      DVersion: 2.079.1
+      DVersion: 2.082.1
       arch: x64
     - DC: dmd
-      DVersion: 2.079.1
-      arch: x86
-    - DC: dmd
-      DVersion: 2.078.3
-      arch: x64
-    - DC: dmd
-      DVersion: 2.078.3
-      arch: x86
-    - DC: dmd
-      DVersion: 2.077.1
-      arch: x64
-    - DC: dmd
-      DVersion: 2.077.1
+      DVersion: 2.082.1
       arch: x86
 
 skip_tags: true
@@ -46,7 +34,7 @@ install:
 before_build:
   - ps: if($env:arch -eq "x86"){
           $env:compilersetupargs = "x86";
-          $env:Darch = "x86";
+          $env:Darch = "x86_mscoff";
         }
         elseif($env:arch -eq "x64"){
           $env:compilersetupargs = "amd64";

arch/build.ninja

@@ -6,9 +6,9 @@ rule archive
 
 build abs.o: gas x64/linux/math/abs.S
 build log.o: gas x64/linux/math/log.S
-build cmp.o: gas x64/linux/memory/cmp.S
+build equal.o: gas x64/linux/memory/equal.S
 build fill.o: gas x64/linux/memory/fill.S
 build copy.o: gas x64/linux/memory/copy.S
 build syscall.o: gas x64/linux/syscall.S
 
-build tanya.a: archive syscall.o copy.o fill.o cmp.o log.o abs.o
+build tanya.a: archive syscall.o copy.o fill.o equal.o log.o abs.o

arch/x64/linux/memory/equal.S

@@ -1,21 +1,19 @@
 	.text
 
 /*
- * cmpMemory.
+ * equalMemory.
  *
  * rdi - r1 length
  * rsi - r1 data.
  * rdx - r2 length.
  * rcx - r2 data.
  */
-	.globl _D5tanya6memory2op9cmpMemoryFNaNbNixAvxAvZi
-	.type _D5tanya6memory2op9cmpMemoryFNaNbNixAvxAvZi, @function
-
-_D5tanya6memory2op9cmpMemoryFNaNbNixAvxAvZi:
+	.globl _D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb
+	.type _D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb, @function
+_D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb:
 		// Compare the lengths
 		cmp %rdx, %rdi
-		jl  less
-		jg  greater
+		jne not_equal
 
 		mov %rcx, %rdi
 
@@ -27,8 +25,7 @@ _D5tanya6memory2op9cmpMemoryFNaNbNixAvxAvZi:
 
 	naligned:
 		cmpsb
-		jl less
-		jg greater
+		jne not_equal
 
 		dec %rdx
 		test $0x07, %edi
@@ -39,29 +36,24 @@ _D5tanya6memory2op9cmpMemoryFNaNbNixAvxAvZi:
 		shr $0x03, %rcx
 
 		repe cmpsq
-		jl less
-		jg greater
+		jne not_equal
 
 		and $0x07, %edx
 		jz equal
 
 	aligned_1: // Compare the remaining bytes
 		mov %rdx, %rcx
+		cmp $0x0, %rcx
 
 		repe cmpsb
-		jl less
-		jg greater
+		jne not_equal
 
 	equal:
+		mov $0x01, %rax // Return 1
+		jmp end
+
+	not_equal:
 		xor %rax, %rax // Return 0
-		jmp end
-
-	greater:
-		mov $0x01, %rax
-		jmp end
-
-	less:
-		mov $-0x01, %rax
 
 	end:
 		ret

arch/x64/linux/syscall.S

@@ -11,10 +11,11 @@ The returned value is placed in %rax.
 */
 	.text
 
-	.globl syscall1
-	.type syscall1, @function
+// 1 parameter.
+	.globl _D5tanya3sys5linux7syscallQiFNbNillZl
+	.type _D5tanya3sys5linux7syscallQiFNbNillZl, @function
 
-syscall1:
+_D5tanya3sys5linux7syscallQiFNbNillZl:
 	movq %rsi, %rax // Syscall number.
 
 	syscall
@@ -23,10 +24,10 @@ syscall1:
 
 
 // 2 parameters.
-	.globl _D5tanya3sys5linux7syscall7syscallFNbNilllZl
-	.type _D5tanya3sys5linux7syscall7syscallFNbNilllZl, @function
+	.globl _D5tanya3sys5linux7syscallQiFNbNilllZl
+	.type _D5tanya3sys5linux7syscallQiFNbNilllZl, @function
 
-_D5tanya3sys5linux7syscall7syscallFNbNilllZl:
+_D5tanya3sys5linux7syscallQiFNbNilllZl:
 	movq %rdx, %rax
 
 	syscall
@@ -34,11 +35,23 @@ _D5tanya3sys5linux7syscall7syscallFNbNilllZl:
 	ret
 
 
-// 6 parameters.
-	.globl _D5tanya3sys5linux7syscall7syscallFNbNilllllllZl
-	.type _D5tanya3sys5linux7syscall7syscallFNbNilllllllZl, @function
+// 3 parameters.
+	.globl _D5tanya3sys5linux7syscallQiFNbNillllZl
+	.type _D5tanya3sys5linux7syscallQiFNbNillllZl, @function
 
-_D5tanya3sys5linux7syscall7syscallFNbNilllllllZl:
+_D5tanya3sys5linux7syscallQiFNbNillllZl:
+	movq %rcx, %rax
+
+	syscall
+
+	ret
+
+
+// 6 parameters.
+	.globl _D5tanya3sys5linux7syscallQiFNbNilllllllZl
+	.type _D5tanya3sys5linux7syscallQiFNbNilllllllZl, @function
+
+_D5tanya3sys5linux7syscallQiFNbNilllllllZl:
 	pushq %rbp
 	movq %rsp, %rbp
 

dub.json

@@ -34,5 +34,7 @@
 		}
 	],
 
-	"libs-windows": ["advapi32"]
+	"libs-windows": ["advapi32"],
+	"libs-windows-x86_mscoff": ["iphlpapi"],
+	"libs-windows-x86_64": ["iphlpapi"]
 }

source/tanya/algorithm/comparison.d

@@ -15,7 +15,8 @@
 module tanya.algorithm.comparison;
 
 import tanya.algorithm.mutation;
-import tanya.math : isNaN;
+import tanya.math;
+static import tanya.memory.op;
 import tanya.meta.metafunction;
 import tanya.meta.trait;
 import tanya.meta.transform;
@@ -270,3 +271,193 @@ if (isForwardRange!Range && isOrderingComparable!(ElementType!Range))
         assert(max(s2, s3).s == 3);
     }
 }
+
+/**
+ * Compares element-wise two ranges for equality.
+ *
+ * If the ranges have different lengths, they aren't equal.
+ *
+ * Params:
+ *  pred = Predicate used to compare individual element pairs.
+ *  R1   = First range type.
+ *  R2   = Second range type.
+ *  r1   = First range.
+ *  r2   = Second range.
+ *
+ * Returns: $(D_KEYWORD true) if both ranges are equal, $(D_KEYWORD false)
+ *          otherwise.
+ */
+bool equal(alias pred = (auto ref a, auto ref b) => a == b, R1, R2)
+          (R1 r1, R2 r2)
+if (allSatisfy!(isInputRange, R1, R2)
+ && is(typeof(pred(r1.front, r2.front)) == bool))
+{
+    static if (isDynamicArray!R1
+            && is(R1 == R2)
+            && __traits(isPOD, ElementType!R1))
+    {
+        return tanya.memory.op.equal(r1, r2);
+    }
+    else
+    {
+        static if (hasLength!R1 && hasLength!R2)
+        {
+            if (r1.length != r2.length)
+            {
+                return false;
+            }
+        }
+        for (; !r1.empty && !r2.empty; r1.popFront(), r2.popFront())
+        {
+            if (!pred(r1.front, r2.front))
+            {
+                return false;
+            }
+        }
+        static if (hasLength!R1 && hasLength!R2)
+        {
+            return true;
+        }
+        else
+        {
+            return r1.empty && r2.empty;
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    int[2] range1 = [1, 2];
+    assert(equal(range1[], range1[]));
+
+    int[3] range2 = [1, 2, 3];
+    assert(!equal(range1[], range2[]));
+}
+
+/**
+ * Compares element-wise two ranges for ordering.
+ *
+ * $(D_PSYMBOL compare) returns a negative value if $(D_PARAM r1) is less than
+ * $(D_PARAM r2), a positive value if $(D_PARAM r2) is less than $(D_PARAM r1),
+ * or `0` if $(D_PARAM r1) and $(D_PARAM r2) equal.
+ *
+ * $(D_PSYMBOL compare) iterates both ranges in lockstep. Whichever of them
+ * contains an element that is greater than the respective element at the same
+ * position in the other range is the greater one of the two.
+ *
+ * If one of the ranges becomes empty when iterating, but all elements equal so
+ * far, the range with more elements is the greater one.
+ *
+ * If $(D_PARAM pred) is given, it is used for comparison. $(D_PARAM pred) is
+ * called as $(D_INLINECODE pred(r1.front, r2.front)) and
+ * $(D_INLINECODE pred(r2.front, r1.front)) to perform three-way comparison.
+ * $(D_PARAM pred) should return a $(D_KEYWORD bool).
+ *
+ * If $(D_PARAM pred) is not given, but the element type of $(D_PARAM R1)
+ * defines `opCmp()` for the element type of $(D_PARAM R2), `opCmp()` is used.
+ *
+ * Otherwise the comparison is perfomed using the basic comparison operators.
+ *
+ * Params:
+ *  pred = Predicate used for comparison.
+ *  R1   = First range type.
+ *  R2   = Second range type.
+ *  r1   = First range.
+ *  r2   = Second range.
+ *
+ * Returns: A negative value if $(D_PARAM r1) is less than $(D_PARAM r2), a
+ *          positive value if $D(_PARAM r2) is less than $(D_PARAM r1), `0`
+ *          otherwise.
+ */
+int compare(alias pred, R1, R2)(R1 r1, R2 r2)
+if (allSatisfy!(isInputRange, R1, R2)
+ && is(typeof(pred(r1.front, r2.front)) == bool)
+ && is(typeof(pred(r2.front, r1.front)) == bool))
+{
+    alias predImpl = (ref r1, ref r2) {
+        return pred(r2.front, r1.front) - pred(r1.front, r2.front);
+    };
+    return compareImpl!(predImpl, R1, R2)(r1, r2);
+}
+
+/// ditto
+int compare(R1, R2)(R1 r1, R2 r2)
+if (allSatisfy!(isInputRange, R1, R2)
+ && is(typeof(r1.front < r2.front || r2.front < r1.front)))
+{
+    static if (is(typeof(r1.front.opCmp(r2.front)) == int))
+    {
+        alias pred = (ref r1, ref r2) => r1.front.opCmp(r2.front);
+    }
+    else
+    {
+        alias pred = (ref r1, ref r2) {
+            return (r2.front < r1.front) - (r1.front < r2.front);
+        };
+    }
+    return compareImpl!(pred, R1, R2)(r1, r2);
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    assert(compare("abc", "abc") == 0);
+    assert(compare("abcd", "abc") > 0);
+    assert(compare("ab", "abc") < 0);
+    assert(compare("abc", "abcd") < 0);
+    assert(compare("abc", "ab") > 0);
+    assert(compare("aec", "abc") > 0);
+    assert(compare("aac", "abc") < 0);
+    assert(compare("abc", "aec") < 0);
+    assert(compare("abc", "aab") > 0);
+    assert(compare("aacd", "abc") < 0);
+    assert(compare("abc", "aacd") > 0);
+
+    assert(compare!((a, b) => a > b)("aec", "abc") < 0);
+    assert(compare!((a, b) => a > b)("aac", "abc") > 0);
+}
+
+private int compareImpl(alias pred, R1, R2)(ref R1 r1, ref R2 r2)
+{
+    for (; !r1.empty || !r2.empty; r1.popFront(), r2.popFront())
+    {
+        if (r1.empty)
+        {
+            return -1;
+        }
+        else if (r2.empty)
+        {
+            return 1;
+        }
+        const comparison = pred(r1, r2);
+        if (comparison != 0)
+        {
+            return comparison;
+        }
+    }
+    return 0;
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static struct OpCmp(int value)
+    {
+        int opCmp(OpCmp) @nogc nothrow pure @safe
+        {
+            return value;
+        }
+    }
+    {
+        OpCmp!(-1)[1] range;
+        assert(compare(range[], range[]) < 0);
+    }
+    {
+        OpCmp!1[1] range;
+        assert(compare(range[], range[]) > 0);
+    }
+    {
+        OpCmp!0[1] range;
+        assert(compare(range[], range[]) == 0);
+    }
+}

source/tanya/algorithm/iteration.d

@@ -0,0 +1,648 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Iteration algorithms.
+ *
+ * These algorithms wrap other ranges and modify the way, how the original
+ * range is iterated, or the order in which its elements are accessed.
+ *
+ * All algorithms in this module are lazy, they request the next element of the
+ * original range on demand.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/algorithm/iteration.d,
+ *                 tanya/algorithm/iteration.d)
+ */
+module tanya.algorithm.iteration;
+
+import tanya.algorithm.comparison;
+import tanya.algorithm.mutation;
+import tanya.range;
+version (unittest) import tanya.test.stub;
+
+private struct Take(R, bool exactly)
+{
+    private R source;
+    size_t length_;
+
+    @disable this();
+
+    private this(R source, size_t length)
+    {
+        this.source = source;
+        static if (!exactly && hasLength!R)
+        {
+            this.length_ = min(source.length, length);
+        }
+        else
+        {
+            this.length_ = length;
+        }
+    }
+
+    @property auto ref front()
+    in
+    {
+        assert(!empty);
+    }
+    do
+    {
+        return this.source.front;
+    }
+
+    void popFront()
+    in
+    {
+        assert(!empty);
+    }
+    do
+    {
+        this.source.popFront();
+        --this.length_;
+    }
+
+    @property bool empty()
+    {
+        static if (exactly || isInfinite!R)
+        {
+            return length == 0;
+        }
+        else
+        {
+            return this.length_ == 0 || this.source.empty;
+        }
+    }
+
+    static if (exactly || hasLength!R)
+    {
+        @property size_t length()
+        {
+            return this.length_;
+        }
+    }
+
+    static if (hasAssignableElements!R)
+    {
+        @property void front(ref ElementType!R value)
+        in
+        {
+            assert(!empty);
+        }
+        do
+        {
+            this.source.front = value;
+        }
+
+        @property void front(ElementType!R value)
+        in
+        {
+            assert(!empty);
+        }
+        do
+        {
+            this.source.front = move(value);
+        }
+    }
+
+    static if (isForwardRange!R)
+    {
+        typeof(this) save()
+        {
+            return typeof(this)(this.source.save(), length);
+        }
+    }
+    static if (isRandomAccessRange!R)
+    {
+        @property auto ref back()
+        in
+        {
+            assert(!empty);
+        }
+        do
+        {
+            return this.source[this.length - 1];
+        }
+
+        void popBack()
+        in
+        {
+            assert(!empty);
+        }
+        do
+        {
+            --this.length_;
+        }
+
+        auto ref opIndex(size_t i)
+        in
+        {
+            assert(i < length);
+        }
+        do
+        {
+            return this.source[i];
+        }
+
+        static if (hasAssignableElements!R)
+        {
+            @property void back(ref ElementType!R value)
+            in
+            {
+                assert(!empty);
+            }
+            do
+            {
+                this.source[length - 1] = value;
+            }
+
+            @property void back(ElementType!R value)
+            in
+            {
+                assert(!empty);
+            }
+            do
+            {
+                this.source[length - 1] = move(value);
+            }
+
+            void opIndexAssign(ref ElementType!R value, size_t i)
+            in
+            {
+                assert(i < length);
+            }
+            do
+            {
+                this.source[i] = value;
+            }
+
+            void opIndexAssign(ElementType!R value, size_t i)
+            in
+            {
+                assert(i < length);
+            }
+            do
+            {
+                this.source[i] = move(value);
+            }
+        }
+    }
+
+    static if (!exactly && hasSlicing!R)
+    {
+        auto opSlice(size_t i, size_t j)
+        in
+        {
+            assert(i <= j);
+            assert(j <= length);
+        }
+        do
+        {
+            return typeof(this)(this.source[i .. j], length);
+        }
+    }
+
+    version (unittest) static assert(isInputRange!Take);
+}
+
+/**
+ * Takes $(D_PARAM n) elements from $(D_PARAM range).
+ *
+ * If $(D_PARAM range) doesn't have $(D_PARAM n) elements, the resulting range
+ * spans all elements of $(D_PARAM range).
+ *
+ * $(D_PSYMBOL take) is particulary useful with infinite ranges. You can take
+ ` $(B n) elements from such range and pass the result to an algorithm which
+ * expects a finit range.
+ *
+ * Params:
+ *  R     = Type of the adapted range.
+ *  range = The range to take the elements from.
+ *  n     = The number of elements to take.
+ *
+ * Returns: A range containing maximum $(D_PARAM n) first elements of
+ *          $(D_PARAM range).
+ *
+ * See_Also: $(D_PSYMBOL takeExactly).
+ */
+auto take(R)(R range, size_t n)
+if (isInputRange!R)
+{
+    static if (hasSlicing!R && hasLength!R)
+    {
+        if (range.length <= n)
+            return range;
+        else
+            return range[0 .. n];
+    }
+    // Special case: take(take(...), n)
+    else static if (is(Range == Take!(RRange, exact), RRange, bool exact))
+    {
+        if (n > range.length_)
+            n = range.length_;
+        static if (exact)
+            // `take(takeExactly(r, n0), n)` is rewritten `takeExactly(r, min(n0, n))`.
+            return Take!(RRange, true)(range.source, n);
+        else
+            // `take(take(r, n0), n)` is rewritten `take(r, min(n0, n))`.
+            return Take!(RRange, false)(range.source, n);
+    }
+    else static if (isInfinite!R)
+    {
+        // If the range is infinite then `take` is the same as `takeExactly`.
+        return Take!(R, true)(range, n);
+    }
+    else
+    {
+        return Take!(R, false)(range, n);
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static struct InfiniteRange
+    {
+        private size_t front_ = 1;
+
+        enum bool empty = false;
+
+        @property size_t front() @nogc nothrow pure @safe
+        {
+            return this.front_;
+        }
+
+        @property void front(size_t i) @nogc nothrow pure @safe
+        {
+            this.front_ = i;
+        }
+
+        void popFront() @nogc nothrow pure @safe
+        {
+            ++this.front_;
+        }
+
+        size_t opIndex(size_t i) @nogc nothrow pure @safe
+        {
+            return this.front_ + i;
+        }
+
+        void opIndexAssign(size_t value, size_t i) @nogc nothrow pure @safe
+        {
+            this.front = i + value;
+        }
+
+        InfiniteRange save() @nogc nothrow pure @safe
+        {
+            return this;
+        }
+    }
+
+    auto t = InfiniteRange().take(3);
+    assert(t.length == 3);
+    assert(t.front == 1);
+    assert(t.back == 3);
+
+    t.popFront();
+    assert(t.front == 2);
+    assert(t.back == 3);
+
+    t.popBack();
+    assert(t.front == 2);
+    assert(t.back == 2);
+
+    t.popFront();
+    assert(t.empty);
+}
+
+// length is unknown when taking from a range without length
+@nogc nothrow pure @safe unittest
+{
+    static struct R
+    {
+        mixin InputRangeStub;
+    }
+    auto actual = take(R(), 100);
+
+    static assert(!hasLength!(typeof(actual)));
+}
+
+/**
+ * Takes exactly $(D_PARAM n) elements from $(D_PARAM range).
+ *
+ * $(D_PARAM range) must have at least $(D_PARAM n) elements.
+ *
+ * $(D_PSYMBOL takeExactly) is particulary useful with infinite ranges. You can
+ ` take $(B n) elements from such range and pass the result to an algorithm
+ * which expects a finit range.
+ *
+ * Params:
+ *  R     = Type of the adapted range.
+ *  range = The range to take the elements from.
+ *  n     = The number of elements to take.
+ *
+ * Returns: A range containing $(D_PARAM n) first elements of $(D_PARAM range).
+ *
+ * See_Also: $(D_PSYMBOL take).
+ */
+auto takeExactly(R)(R range, size_t n)
+if (isInputRange!R)
+{
+    static if (hasSlicing!R)
+    {
+        return range[0 .. n];
+    }
+    // Special case: takeExactly(take(range, ...), n) is takeExactly(range, n)
+    else static if (is(Range == Take!(RRange, exact), RRange, bool exact))
+    {
+        assert(n <= range.length_);
+        return Take!(RRange, true)(range.source, n);
+    }
+    else
+    {
+        return Take!(R, true)(range, n);
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static struct InfiniteRange
+    {
+        private size_t front_ = 1;
+
+        enum bool empty = false;
+
+        @property size_t front() @nogc nothrow pure @safe
+        {
+            return this.front_;
+        }
+
+        @property void front(size_t i) @nogc nothrow pure @safe
+        {
+            this.front_ = i;
+        }
+
+        void popFront() @nogc nothrow pure @safe
+        {
+            ++this.front_;
+        }
+
+        size_t opIndex(size_t i) @nogc nothrow pure @safe
+        {
+            return this.front_ + i;
+        }
+
+        void opIndexAssign(size_t value, size_t i) @nogc nothrow pure @safe
+        {
+            this.front = i + value;
+        }
+
+        InfiniteRange save() @nogc nothrow pure @safe
+        {
+            return this;
+        }
+    }
+
+    auto t = InfiniteRange().takeExactly(3);
+    assert(t.length == 3);
+    assert(t.front == 1);
+    assert(t.back == 3);
+
+    t.popFront();
+    assert(t.front == 2);
+    assert(t.back == 3);
+
+    t.popBack();
+    assert(t.front == 2);
+    assert(t.back == 2);
+
+    t.popFront();
+    assert(t.empty);
+}
+
+// Takes minimum length if the range length > n
+@nogc nothrow pure @safe unittest
+{
+    auto range = take(cast(int[]) null, 8);
+    assert(range.length == 0);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    const int[9] range = [1, 2, 3, 4, 5, 6, 7, 8, 9];
+    {
+        auto slice = take(range[], 8)[1 .. 3];
+
+        assert(slice.length == 2);
+        assert(slice.front == 2);
+        assert(slice.back == 3);
+    }
+    {
+        auto slice = takeExactly(range[], 8)[1 .. 3];
+
+        assert(slice.length == 2);
+        assert(slice.front == 2);
+        assert(slice.back == 3);
+    }
+}
+
+// Reverse-access-order range returned by `retro`.
+private struct Retro(Range)
+{
+    Range source;
+
+    @disable this();
+
+    private this(Range source)
+    {
+        this.source = source;
+    }
+
+    Retro save()
+    {
+        return this;
+    }
+
+    @property auto ref front()
+    in (!empty)
+    {
+        return this.source.back;
+    }
+
+    void popFront()
+    in (!empty)
+    {
+        this.source.popBack();
+    }
+
+    @property auto ref back()
+    in (!empty)
+    {
+        return this.source.front;
+    }
+
+    void popBack()
+    in (!empty)
+    {
+        this.source.popFront();
+    }
+
+    @property bool empty()
+    {
+        return this.source.empty;
+    }
+
+    static if (hasLength!Range)
+    {
+        @property size_t length()
+        {
+            return this.source.length;
+        }
+    }
+
+    static if (isRandomAccessRange!Range && hasLength!Range)
+    {
+        auto ref opIndex(size_t i)
+        in (i < length)
+        {
+            return this.source[$ - ++i];
+        }
+    }
+
+    static if (hasLength!Range && hasSlicing!Range)
+    {
+        alias opDollar = length;
+
+        auto opSlice(size_t i, size_t j)
+        in
+        {
+            assert(i <= j);
+            assert(j <= length);
+        }
+        do
+        {
+            return typeof(this)(this.source[$-j .. $-i]);
+        }
+    }
+
+    static if (hasAssignableElements!Range)
+    {
+        @property void front(ref ElementType!Range value)
+        in (!empty)
+        {
+            this.source.back = value;
+        }
+
+        @property void front(ElementType!Range value)
+        in (!empty)
+        {
+            this.source.back = move(value);
+        }
+
+        @property void back(ref ElementType!Range value)
+        in (!empty)
+        {
+            this.source.front = value;
+        }
+
+        @property void back(ElementType!Range value)
+        in (!empty)
+        {
+            this.source.front = move(value);
+        }
+
+        static if (isRandomAccessRange!Range && hasLength!Range)
+        {
+            void opIndexAssign(ref ElementType!Range value, size_t i)
+            in (i < length)
+            {
+                this.source[$ - ++i] = value;
+            }
+
+            void opIndexAssign(ElementType!Range value, size_t i)
+            in (i < length)
+            {
+                this.source[$ - ++i] = move(value);
+            }
+        }
+    }
+
+    version (unittest) static assert(isBidirectionalRange!Retro);
+}
+
+/**
+ * Iterates a bidirectional range backwards.
+ *
+ * If $(D_PARAM Range) is a random-access range as well, the resulting range
+ * is a random-access range too.
+ *
+ * Params:
+ *  Range = Bidirectional range type.
+ *  range = Bidirectional range.
+ *
+ * Returns: Bidirectional range with the elements order reversed.
+ */
+auto retro(Range)(return Range range)
+if (isBidirectionalRange!Range)
+{
+    // Special case: retro(retro(range)) is range
+    static if (is(Range == Retro!RRange, RRange))
+        return range.source;
+    else
+        return Retro!Range(range);
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[3] given = [1, 2, 3];
+    const int[3] expected = [3, 2, 1];
+
+    auto actual = retro(given[]);
+
+    assert(actual.length == expected.length);
+    assert(!actual.empty);
+    assert(equal(actual, expected[]));
+}
+
+// Elements are accessible in reverse order
+@nogc nothrow pure @safe unittest
+{
+    const int[3] given = [1, 2, 3];
+    auto actual = retro(given[]);
+
+    assert(actual.back == given[].front);
+    assert(actual[0] == 3);
+    assert(actual[2] == 1);
+
+    actual.popBack();
+    assert(actual.back == 2);
+    assert(actual[1] == 2);
+
+    // Check slicing.
+    auto slice = retro(given[])[1 .. $];
+    assert(slice.length == 2 && slice.front == 2 && slice.back == 1);
+}
+
+// Elements can be assigned
+@nogc nothrow pure @safe unittest
+{
+    int[4] given = [1, 2, 3, 4];
+    auto actual = retro(given[]);
+
+    actual.front = 5;
+    assert(given[].back == 5);
+
+    actual.back = 8;
+    assert(given[].front == 8);
+
+    actual[2] = 10;
+    assert(given[1] == 10);
+}

source/tanya/algorithm/mutation.d

@@ -5,7 +5,7 @@
 /**
  * Algorithms that modify its arguments.
  *
- * Copyright: Eugene Wissner 2017-2018.
+ * Copyright: Eugene Wissner 2017-2019.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -14,8 +14,12 @@
  */
 module tanya.algorithm.mutation;
 
-import tanya.memory.op;
+import tanya.conv;
+static import tanya.memory.op;
 import tanya.meta.trait;
+import tanya.meta.transform;
+import tanya.range;
+version (unittest) import tanya.test.stub;
 
 private void deinitialize(bool zero, T)(ref T value)
 {
@@ -39,11 +43,12 @@ private void deinitialize(bool zero, T)(ref T value)
         }
         static if (zero)
         {
-            fill!0((cast(void*) &value)[0 .. size]);
+            tanya.memory.op.fill!0((cast(void*) &value)[0 .. size]);
         }
         else
         {
-            copy(typeid(T).initializer()[0 .. size], (&value)[0 .. 1]);
+            tanya.memory.op.copy(typeid(T).initializer()[0 .. size],
+                                 (&value)[0 .. 1]);
         }
     }
 }
@@ -81,17 +86,24 @@ do
 {
     static if (is(T == struct) || isStaticArray!T)
     {
-        copy((&source)[0 .. 1], (&target)[0 .. 1]);
+        tanya.memory.op.copy((&source)[0 .. 1], (&target)[0 .. 1]);
 
         static if (hasElaborateCopyConstructor!T || hasElaborateDestructor!T)
         {
-            if (typeid(T).initializer().ptr is null)
+            static if (__VERSION__ >= 2083) // __traits(isZeroInit) available.
             {
-                deinitialize!true(source);
+                deinitialize!(__traits(isZeroInit, T))(source);
             }
             else
             {
-                deinitialize!false(source);
+                if (typeid(T).initializer().ptr is null)
+                {
+                    deinitialize!true(source);
+                }
+                else
+                {
+                    deinitialize!false(source);
+                }
             }
         }
     }
@@ -211,9 +223,16 @@ void move(T)(ref T source, ref T target)
 /// ditto
 T move(T)(ref T source) @trusted
 {
-    T target = void;
-    moveEmplace(source, target);
-    return target;
+    static if (hasElaborateCopyConstructor!T || hasElaborateDestructor!T)
+    {
+        T target = void;
+        moveEmplace(source, target);
+        return target;
+    }
+    else
+    {
+        return source;
+    }
 }
 
 ///
@@ -273,3 +292,408 @@ void swap(T)(ref T a, ref T b) @trusted
     assert(a == 5);
     assert(b == 3);
 }
+
+/**
+ * Copies the $(D_PARAM source) range into the $(D_PARAM target) range.
+ *
+ * Params:
+ *  Source = Input range type.
+ *  Target = Output range type.
+ *  source = Source input range.
+ *  target = Target output range.
+ *
+ * Returns: $(D_PARAM target) range, whose front element is the one past the
+ *          last element copied.
+ *
+ * Precondition: $(D_PARAM target) should be large enough to accept all
+ *               $(D_PARAM source) elements.
+ */
+Target copy(Source, Target)(Source source, Target target)
+if (isInputRange!Source && isOutputRange!(Target, Source))
+in
+{
+    static if (hasLength!Source && hasLength!Target)
+    {
+        assert(target.length >= source.length);
+    }
+}
+do
+{
+    alias E = ElementType!Source;
+    static if (isDynamicArray!Source
+            && is(Unqual!E == ElementType!Target)
+            && !hasElaborateCopyConstructor!E
+            && !hasElaborateAssign!E
+            && !hasElaborateDestructor!E)
+    {
+        if (source.ptr < target.ptr
+         && (() @trusted => (target.ptr - source.ptr) < source.length)())
+        {
+            tanya.memory.op.copyBackward(source, target);
+        }
+        else if (source.ptr !is target.ptr)
+        {
+            tanya.memory.op.copy(source, target);
+        }
+        return target[source.length .. $];
+    }
+    else
+    {
+        for (; !source.empty; source.popFront())
+        {
+            put(target, source.front);
+        }
+        return target;
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[2] source = [1, 2];
+    int[2] target = [3, 4];
+
+    copy(source[], target[]);
+    assert(equal(source[], target[]));
+}
+
+// Returns advanced target
+@nogc nothrow pure @safe unittest
+{
+    int[5] input = [1, 2, 3, 4, 5];
+    assert(copy(input[3 .. 5], input[]).front == 3);
+}
+
+// Copies overlapping arrays
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    int[6] actual = [1, 2, 3, 4, 5, 6];
+    const int[6] expected = [1, 2, 1, 2, 3, 4];
+
+    copy(actual[0 .. 4], actual[2 .. 6]);
+    assert(equal(actual[], expected[]));
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(typeof(copy((ubyte[]).init, (ushort[]).init))));
+    static assert(!is(typeof(copy((ushort[]).init, (ubyte[]).init))));
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static struct OutPutRange
+    {
+        int value;
+        void put(int value) @nogc nothrow pure @safe
+        in
+        {
+            assert(this.value == 0);
+        }
+        do
+        {
+            this.value = value;
+        }
+    }
+    int[1] source = [5];
+    OutPutRange target;
+
+    assert(copy(source[], target).value == 5);
+}
+
+/**
+ * Fills $(D_PARAM range) with $(D_PARAM value).
+ *
+ * Params:
+ *  Range = Input range type.
+ *  Value = Filler type.
+ *  range = Input range.
+ *  value = Filler.
+ */
+void fill(Range, Value)(Range range, auto ref Value value)
+if (isInputRange!Range && isAssignable!(ElementType!Range, Value))
+{
+    static if (!isDynamicArray!Range && is(typeof(range[] = value)))
+    {
+        range[] = value;
+    }
+    else
+    {
+        for (; !range.empty; range.popFront())
+        {
+            range.front = value;
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    int[6] actual;
+    const int[6] expected = [1, 1, 1, 1, 1, 1];
+
+    fill(actual[], 1);
+    assert(equal(actual[], expected[]));
+}
+
+// [] is called where possible
+@nogc nothrow pure @system unittest
+{
+    static struct Slice
+    {
+        bool* slicingCalled;
+
+        int front() @nogc nothrow pure @safe
+        {
+            return 0;
+        }
+
+        void front(int) @nogc nothrow pure @safe
+        {
+        }
+
+        void popFront() @nogc nothrow pure @safe
+        {
+        }
+
+        bool empty() @nogc nothrow pure @safe
+        {
+            return true;
+        }
+
+        void opIndexAssign(int) @nogc nothrow pure @safe
+        {
+            *this.slicingCalled = true;
+        }
+    }
+    bool slicingCalled;
+    auto range = Slice(&slicingCalled);
+    fill(range, 0);
+    assert(slicingCalled);
+}
+
+/**
+ * Fills $(D_PARAM range) with $(D_PARAM value) assuming the elements of the
+ * $(D_PARAM range) aren't initialized.
+ *
+ * Params:
+ *  Range = Input range type.
+ *  Value = Initializer type.
+ *  range = Input range.
+ *  value = Initializer.
+ */
+void uninitializedFill(Range, Value)(Range range, auto ref Value value)
+if (isInputRange!Range && hasLvalueElements!Range
+ && isAssignable!(ElementType!Range, Value))
+{
+    static if (hasElaborateDestructor!(ElementType!Range))
+    {
+        for (; !range.empty; range.popFront())
+        {
+            ElementType!Range* p = &range.front;
+            emplace!(ElementType!Range)(cast(void[]) (p[0 .. 1]), value);
+        }
+    }
+    else
+    {
+        fill(range, value);
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    int[6] actual = void;
+    const int[6] expected = [1, 1, 1, 1, 1, 1];
+
+    uninitializedFill(actual[], 1);
+    assert(equal(actual[], expected[]));
+}
+
+/**
+ * Initializes all elements of the $(D_PARAM range) assuming that they are
+ * uninitialized.
+ *
+ * Params:
+ *  Range = Input range type
+ *  range = Input range.
+ */
+void initializeAll(Range)(Range range) @trusted
+if (isInputRange!Range && hasLvalueElements!Range)
+{
+    import tanya.memory.op : copy, fill;
+    alias T = ElementType!Range;
+
+    static if (__VERSION__ >= 2083
+            && isDynamicArray!Range
+            && __traits(isZeroInit, T))
+    {
+        fill!0(range);
+    }
+    else
+    {
+        static immutable init = T.init;
+        for (; !range.empty; range.popFront())
+        {
+            copy((&init)[0 .. 1], (&range.front)[0 .. 1]);
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    int[2] actual = void;
+    const int[2] expected = [0, 0];
+
+    initializeAll(actual[]);
+    assert(equal(actual[], expected[]));
+}
+
+@nogc nothrow pure @safe unittest
+{
+    NonCopyable[] nonCopyable;
+    initializeAll(nonCopyable);
+}
+
+/**
+ * Destroys all elements in the $(D_PARAM range).
+ *
+ * This function has effect only if the element type of $(D_PARAM Range) has
+ * an elaborate destructor, i.e. it is a $(D_PSYMBOL struct) with an explicit
+ * or generated by the compiler destructor.
+ *
+ * Params:
+ *  Range = Input range type.
+ *  range = Input range.
+ */
+void destroyAll(Range)(Range range)
+if (isInputRange!Range && hasLvalueElements!Range)
+{
+    static if (hasElaborateDestructor!(ElementType!Range))
+    {
+        foreach (ref e; range)
+        {
+            destroy(e);
+        }
+    }
+}
+
+///
+@nogc nothrow pure @trusted unittest
+{
+    static struct WithDtor
+    {
+        private size_t* counter;
+        ~this() @nogc nothrow pure
+        {
+            if (this.counter !is null)
+            {
+                ++(*this.counter);
+            }
+        }
+    }
+
+    size_t counter;
+    WithDtor[2] withDtor = [WithDtor(&counter), WithDtor(&counter)];
+
+    destroyAll(withDtor[]);
+
+    assert(counter == 2);
+}
+
+/**
+ * Rotates the elements of a union of two ranges.
+ *
+ * Performs a left rotation on the given ranges, as if it would be a signle
+ * range, so that [`front.front`, `back.front`$(RPAREN) is a valid range, that
+ * is $(D_PARAM back) would continue $(D_PARAM front).
+ *
+ * The elements are moved so, that the first element of $(D_PARAM back) becomes
+ * the first element of $(D_PARAM front) without changing the relative order of
+ * their elements.
+ *
+ * Params:
+ *  Range = Range type.
+ *  front = Left half.
+ *  back  = Right half.
+ */
+void rotate(Range)(Range front, Range back)
+if (isForwardRange!Range && hasSwappableElements!Range)
+{
+    auto next = back.save();
+
+    while (!front.empty && !next.empty && !sameHead(front, next))
+    {
+        swap(front.front, next.front);
+        front.popFront();
+        next.popFront();
+
+        if (next.empty)
+        {
+            next = back.save();
+        }
+        else if (front.empty)
+        {
+            front = back.save();
+            back = next.save();
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[7] expected = [1, 2, 3, 4, 5, 6, 7];
+    int[7] actual = [5, 6, 3, 4, 1, 2, 7];
+
+    rotate(actual[0 .. 2], actual[4 .. 6]);
+    assert(equal(actual[], expected[]));
+}
+
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[5] expected = [1, 2, 3, 4, 5];
+    int[5] actual = [4, 5, 1, 2, 3];
+
+    rotate(actual[0 .. 2], actual[2 .. $]);
+    assert(equal(actual[], expected[]));
+}
+
+// Doesn't cause an infinite loop if back is shorter than the front
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[5] expected = [1, 2, 3, 4, 5];
+    int[5] actual = [3, 4, 5, 1, 2];
+
+    rotate(actual[0 .. 3], actual[3 .. $]);
+    assert(equal(actual[], expected[]));
+}
+
+// Doesn't call .front on an empty front
+@nogc nothrow pure @safe unittest
+{
+    import tanya.algorithm.comparison : equal;
+
+    const int[2] expected = [2, 8];
+    int[2] actual = expected;
+
+    rotate(actual[0 .. 0], actual[]);
+    assert(equal(actual[], expected[]));
+}

source/tanya/algorithm/package.d

@@ -15,4 +15,5 @@
 module tanya.algorithm;
 
 public import tanya.algorithm.comparison;
+public import tanya.algorithm.iteration;
 public import tanya.algorithm.mutation;

source/tanya/algorithm/searching.d

@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Searching algorithms.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/algorithm/searching.d,
+ *                 tanya/algorithm/searching.d)
+ */
+module tanya.algorithm.searching;
+
+import tanya.range;
+
+/**
+ * Counts the elements in an input range.
+ *
+ * If $(D_PARAM R) has length, $(D_PSYMBOL count) returns it, otherwise it
+ * iterates over the range and counts the elements.
+ *
+ * Params:
+ *  R     = Input range type.
+ *  range = Input range.
+ *
+ * Returns: $(D_PARAM range) length.
+ */
+size_t count(R)(R range)
+if (isInputRange!R)
+{
+    static if (hasLength!R)
+    {
+        return range.length;
+    }
+    else
+    {
+        size_t counter;
+        for (; !range.empty; range.popFront(), ++counter)
+        {
+        }
+        return counter;
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    int[3] array;
+    assert(count(array) == 3);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static struct Range
+    {
+        private int counter = 3;
+
+        int front() const @nogc nothrow pure @safe
+        {
+            return this.counter;
+        }
+
+        void popFront() @nogc nothrow pure @safe
+        {
+            --this.counter;
+        }
+
+        bool empty() const @nogc nothrow pure @safe
+        {
+            return this.counter == 0;
+        }
+    }
+    Range range;
+    assert(count(range) == 3);
+}

source/tanya/async/event/iocp.d

@@ -318,7 +318,9 @@ final class IOCPLoop : Loop
 
                 connection.incoming.insertBack(transport);
 
-                reify(transport, EventMask(Event.none), EventMask(Event.read, Event.write));
+                reify(transport,
+                      EventMask(Event.none),
+                      EventMask(Event.read | Event.write));
 
                 pendings.insertBack(connection);
                 listener.beginAccept(overlapped);

source/tanya/async/event/kqueue.d

@@ -84,12 +84,12 @@ enum : short
 
 struct kevent_t
 {
-    uintptr_t    ident; /* identifier for this event */
-    short       filter; /* filter for event */
-    ushort       flags;
-    uint        fflags;
-    intptr_t      data;
-    void        *udata; /* opaque user data identifier */
+    uintptr_t ident; // Identifier for this event
+    short filter; // Filter for event
+    ushort flags;
+    uint fflags;
+    intptr_t data;
+    void* udata; // Opaque user data identifier
 }
 
 enum
@@ -168,7 +168,7 @@ final class KqueueLoop : SelectorLoop
                filter,
                flags,
                0U,
-               0L,
+               0,
                null);
         ++changeCount;
     }

source/tanya/async/event/selector.d

@@ -140,7 +140,7 @@ package class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
     {
         closing = true;
         loop.reify(this,
-                   EventMask(Event.read, Event.write),
+                   EventMask(Event.read | Event.write),
                    EventMask(Event.write));
     }
 
@@ -393,7 +393,9 @@ abstract class SelectorLoop : Loop
                 transport.socket = client;
             }
 
-            reify(transport, EventMask(Event.none), EventMask(Event.read, Event.write));
+            reify(transport,
+                  EventMask(Event.none),
+                  EventMask(Event.read | Event.write));
             connection.incoming.insertBack(transport);
         }
 

source/tanya/async/loop.d

@@ -13,50 +13,52 @@
  *
  * class EchoProtocol : TransmissionControlProtocol
  * {
- *  private DuplexTransport transport;
+ *     private DuplexTransport transport;
  *
- *  void received(in ubyte[] data) @nogc
- *  {
- *      transport.write(data);
- *  }
+ *     void received(in ubyte[] data) @nogc
+ *     {
+ *         ubyte[512] buffer;
+ *         buffer[0 .. data.length] = data;
+ *         transport.write(buffer[]);
+ *     }
  *
- *  void connected(DuplexTransport transport) @nogc
- *  {
- *      this.transport = transport;
- *  }
+ *     void connected(DuplexTransport transport) @nogc
+ *     {
+ *         this.transport = transport;
+ *     }
  *
- *  void disconnected(SocketException e) @nogc
- *  {
- *  }
+ *     void disconnected(SocketException e) @nogc
+ *     {
+ *     }
  * }
  *
  * void main()
  * {
- *  auto address = defaultAllocator.make!InternetAddress("127.0.0.1", cast(ushort) 8192);
+ *     auto address = defaultAllocator.make!InternetAddress("127.0.0.1", cast(ushort) 8192);
  *
- *  version (Windows)
- *  {
- *      auto sock = defaultAllocator.make!OverlappedStreamSocket(AddressFamily.inet);
- *  }
- *  else
- *  {
- *      auto sock = defaultAllocator.make!StreamSocket(AddressFamily.inet);
- *      sock.blocking = false;
- *  }
+ *     version (Windows)
+ *     {
+ *         auto sock = defaultAllocator.make!OverlappedStreamSocket(AddressFamily.inet);
+ *     }
+ *     else
+ *     {
+ *         auto sock = defaultAllocator.make!StreamSocket(AddressFamily.inet);
+ *         sock.blocking = false;
+ *     }
  *
- *  sock.bind(address);
- *  sock.listen(5);
+ *     sock.bind(address);
+ *     sock.listen(5);
  *
- *  auto io = defaultAllocator.make!ConnectionWatcher(sock);
- *  io.setProtocol!EchoProtocol;
+ *     auto io = defaultAllocator.make!ConnectionWatcher(sock);
+ *     io.setProtocol!EchoProtocol;
  *
- *  defaultLoop.start(io);
- *  defaultLoop.run();
+ *     defaultLoop.start(io);
+ *     defaultLoop.run();
  *
- *  sock.shutdown();
- *  defaultAllocator.dispose(io);
- *  defaultAllocator.dispose(sock);
- *  defaultAllocator.dispose(address);
+ *     sock.shutdown();
+ *     defaultAllocator.dispose(io);
+ *     defaultAllocator.dispose(sock);
+ *     defaultAllocator.dispose(address);
  * }
  * ---
  *
@@ -70,9 +72,9 @@
 module tanya.async.loop;
 
 import core.time;
-import std.typecons;
 import tanya.async.transport;
 import tanya.async.watcher;
+import tanya.bitmanip;
 import tanya.container.buffer;
 import tanya.container.list;
 import tanya.memory;

source/tanya/bitmanip.d

@@ -0,0 +1,359 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Bit manipulation.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/bitmanip.d,
+ *                 tanya/bitmanip.d)
+ */
+module tanya.bitmanip;
+
+import tanya.meta.metafunction;
+import tanya.meta.trait;
+import tanya.meta.transform;
+
+/**
+ * Determines whether $(D_PARAM E) is a $(D_KEYWORD enum), whose members can be
+ * used as bit flags.
+ *
+ * This is the case if all members of $(D_PARAM E) are integral numbers that
+ * are either 0 or positive integral powers of 2.
+ *
+ * Params:
+ *  E = Some $(D_KEYWORD enum).
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM E) contains only bit flags,
+ *          $(D_KEYWORD false) otherwise.
+ */
+template isBitFlagEnum(E)
+{
+    enum bool isValid(OriginalType!E x) = x == 0
+                                       || (x > 0 && ((x & (x - 1)) == 0));
+    static if (isIntegral!E)
+    {
+        enum bool isBitFlagEnum = allSatisfy!(isValid, EnumMembers!E);
+    }
+    else
+    {
+        enum bool isBitFlagEnum = false;
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    enum Valid
+    {
+        none = 0,
+        one = 1 << 0,
+        two = 1 << 1,
+    }
+    static assert(isBitFlagEnum!Valid);
+
+    enum Invalid
+    {
+        one,
+        two,
+        three,
+        four,
+    }
+    static assert(!isBitFlagEnum!Invalid);
+
+    enum Negative
+    {
+        one = -1,
+        two = -2,
+    }
+    static assert(!isBitFlagEnum!Negative);
+}
+
+/**
+ * Validates that $(D_PARAM field) contains only bits from $(D_PARAM E).
+ *
+ * Params:
+ *  E     = Some $(D_KEYWORD enum).
+ *  field = Bit field.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM field) is valid, $(D_KEYWORD false)
+ *          otherwise.
+ */
+bool containsBitFlags(E)(E field)
+if (isBitFlagEnum!E)
+{
+    OriginalType!E fillField()
+    {
+        typeof(return) full;
+        static foreach (member; EnumMembers!E)
+        {
+            full |= member;
+        }
+        return full;
+    }
+    enum OriginalType!E full = fillField();
+    return (field & ~full) == OriginalType!E.init;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    enum E
+    {
+        one,
+        two,
+        three,
+    }
+    assert(containsBitFlags(E.one | E.two));
+    assert(!containsBitFlags(cast(E) 0x8));
+}
+
+/**
+ * Allows to use $(D_KEYWORD enum) values as a set of bit flags.
+ *
+ * $(D_PSYMBOL BitFlags) behaves the same as a bit field of type $(D_PARAM E),
+ * but does additional cheks to ensure that the bit field contains only valid
+ * values, this is only values from $(D_PARAM E).
+ *
+ * Params:
+ *  E = Some $(D_KEYWORD enum).
+ */
+struct BitFlags(E)
+if (isBitFlagEnum!E)
+{
+    private OriginalType!E field;
+
+    /**
+     * Constructs $(D_PSYMBOL BitFlags) from $(D_PARAM field).
+     *
+     * Params:
+     *  field = Bits to be set.
+     */
+    this(E field)
+    {
+        this.field = field;
+    }
+
+    /**
+     * Converts $(D_PSYMBOL BitFlags) to a boolean.
+     *
+     * It is $(D_KEYWORD true) if any bit is set, $(D_KEYWORD false) otherwise.
+     *
+     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL BitFlags) contains any
+     *          set bits, $(D_KEYWORD false) otherwise.
+     */
+    bool opCast(T : bool)()
+    {
+        return this.field != 0;
+    }
+
+    /**
+     * Converts to the original type of $(D_PARAM E) ($(D_KEYWORD int) by
+     * default).
+     *
+     * Returns: $(D_KEYWORD this) as $(D_INLINECODE OriginalType!T).
+     */
+    OriginalType!E opCast(T : OriginalType!E)() const
+    {
+        return this.field;
+    }
+
+    /**
+     * Tests (&), sets (|) or toggles (^) bits.
+     *
+     * Params:
+     *  op   = Operation.
+     *  that = 0 or more bit flags.
+     *
+     * Returns: New $(D_PSYMBOL BitFlags) object.
+     */
+    BitFlags opBinary(string op)(E that) const
+    if (op == "&" || op == "|" || op == "^")
+    {
+        BitFlags result = this;
+        mixin("return result " ~ op ~ "= that;");
+    }
+
+    /// ditto
+    BitFlags opBinary(string op)(BitFlags that) const
+    if (op == "&" || op == "|" || op == "^")
+    {
+        BitFlags result = this;
+        mixin("return result " ~ op ~ "= that;");
+    }
+
+    /// ditto
+    BitFlags opBinaryRight(string op)(E that) const
+    if (op == "&" || op == "|" || op == "^")
+    {
+        BitFlags result = this;
+        mixin("return result " ~ op ~ "= that;");
+    }
+
+    /**
+     * Tests (&), sets (|) or toggles (^) bits.
+     *
+     * Params:
+     *  op   = Operation.
+     *  that = 0 or more bit flags.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref BitFlags opOpAssign(string op)(E that)
+    if (op == "&" || op == "|" || op == "^")
+    {
+        mixin("this.field " ~ op ~ "= that;");
+        return this;
+    }
+
+    /// ditto
+    ref BitFlags opOpAssign(string op)(BitFlags that)
+    if (op == "&" || op == "|" || op == "^")
+    {
+        mixin("this.field " ~ op ~ "= that.field;");
+        return this;
+    }
+
+    /**
+     * Inverts all bit flags.
+     *
+     * Returns: New $(D_PSYMBOL BitFlags) object with all bits inverted.
+     */
+    BitFlags opUnary(string op : "~")() const
+    {
+        BitFlags result;
+        result.field  = ~this.field;
+        return result;
+    }
+
+    /**
+     * Assigns a bit field.
+     *
+     * Params:
+     *  that = Bit field of type $(D_PARAM E).
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref BitFlags opAssign(E that)
+    {
+        this.field = that;
+        return this;
+    }
+
+    /**
+     * Compares this $(D_PSYMBOL BitFlags) object to another bit field.
+     *
+     * Params:
+     *  that = $(D_PSYMBOL BitFlags) object or a bit field of type
+     *         $(D_PARAM E).
+     *
+     * Returns: $(D_KEYWORD true) if $(D_KEYWORD this) and $(D_PARAM that)
+     *          contain the same bits ,$(D_KEYWORD false) otherwise.
+     */
+    bool opEquals(E that) const
+    {
+        return this.field == that;
+    }
+
+    /// ditto
+    bool opEquals(BitFlags that) const
+    {
+        return this.field == that.field;
+    }
+
+    /**
+     * Generates a hash value of this object.
+     *
+     * Returns: Hash value.
+     */
+    size_t toHash() const
+    {
+        return cast(size_t) this.field;
+    }
+}
+
+@nogc nothrow pure @safe unittest
+{
+    enum E : int
+    {
+        one = 1,
+    }
+
+    // Casts to a boolean
+    assert(BitFlags!E(E.one));
+    assert(!BitFlags!E());
+
+    // Assigns to and compares with a single value
+    {
+        BitFlags!E bitFlags;
+        bitFlags = E.one;
+        assert(bitFlags == E.one);
+    }
+    // Assigns to and compares with the same type
+    {
+        auto bitFlags1 = BitFlags!E(E.one);
+        BitFlags!E bitFlags2;
+        bitFlags2 = bitFlags1;
+        assert(bitFlags1 == bitFlags2);
+    }
+    assert((BitFlags!E() | E.one) == BitFlags!E(E.one));
+    assert((BitFlags!E() | BitFlags!E(E.one)) == BitFlags!E(E.one));
+
+    assert(!(BitFlags!E() & BitFlags!E(E.one)));
+
+    assert(!(BitFlags!E(E.one) ^ E.one));
+    assert(BitFlags!E() ^ BitFlags!E(E.one));
+
+    assert(~BitFlags!E());
+
+    assert(BitFlags!E().toHash() == 0);
+    assert(BitFlags!E(E.one).toHash() != 0);
+
+    // opBinaryRight is allowed
+    static assert(is(typeof({ E.one | BitFlags!E(); })));
+}
+
+/**
+ * Creates a $(D_PSYMBOL BitFlags) object initialized with $(D_PARAM field).
+ *
+ * Params:
+ *  E     = Some $(D_KEYWORD enum).
+ *  field = Bits to be set.
+ */
+BitFlags!E bitFlags(E)(E field)
+if (isBitFlagEnum!E)
+{
+    return BitFlags!E(field);
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    enum E
+    {
+        one = 1 << 0,
+        two = 1 << 1,
+        three = 1 << 2,
+    }
+    // Construct with E.one and E.two set
+    auto flags = bitFlags(E.one | E.two);
+
+    // Test wheter E.one is set
+    assert(flags & E.one);
+
+    // Toggle E.one
+    flags ^= E.one;
+    assert(!(flags & E.one));
+
+    // Set E.three
+    flags |= E.three;
+    assert(flags & E.three);
+
+    // Clear E.three
+    flags &= ~E.three;
+    assert(!(flags & E.three));
+}

source/tanya/container/array.d

@@ -15,20 +15,15 @@
 module tanya.container.array;
 
 import core.checkedint;
-import std.algorithm.comparison : equal;
-import std.algorithm.mutation : bringToFront,
-                                copy,
-                                fill,
-                                initializeAll,
-                                uninitializedFill;
-import std.meta;
 import tanya.algorithm.comparison;
 import tanya.algorithm.mutation;
 import tanya.exception;
+import tanya.functional;
 import tanya.memory;
 import tanya.meta.trait;
 import tanya.meta.transform;
-import tanya.range.primitive;
+import tanya.range;
+version (unittest) import tanya.test.stub;
 
 /**
  * Random-access range for the $(D_PSYMBOL Array).
@@ -300,7 +295,9 @@ struct Array(T)
      *  init      = Initial value to fill the array with.
      *  allocator = Allocator.
      */
-    this(size_t len, T init, shared Allocator allocator = defaultAllocator)
+    this()(size_t len,
+           auto ref T init,
+           shared Allocator allocator = defaultAllocator)
     {
         this(allocator);
         reserve(len);
@@ -355,15 +352,19 @@ struct Array(T)
         (() @trusted => allocator.deallocate(slice(capacity)))();
     }
 
-    /**
-     * Copies the array.
-     */
-    this(this)
+    static if (isCopyable!T)
     {
-        auto buf = slice(this.length);
-        this.length_ = capacity_ = 0;
-        this.data = null;
-        insertBack(buf);
+        this(this)
+        {
+            auto buf = slice(this.length);
+            this.length_ = capacity_ = 0;
+            this.data = null;
+            insertBack(buf);
+        }
+    }
+    else
+    {
+        @disable this(this);
     }
 
     /**
@@ -420,27 +421,19 @@ struct Array(T)
      */
     @property void length(size_t len) @trusted
     {
-        if (len == length)
-        {
-            return;
-        }
-        else if (len > length)
+        if (len > length)
         {
             reserve(len);
             initializeAll(this.data[length_ .. len]);
         }
         else
         {
-            static if (hasElaborateDestructor!T)
-            {
-                const T* end = this.data + length_ - 1;
-                for (T* e = this.data + len; e != end; ++e)
-                {
-                    destroy(*e);
-                }
-            }
+            destroyAll(this.data[len .. this.length_]);
+        }
+        if (len != length)
+        {
+            length_ = len;
         }
-        length_ = len;
     }
 
     ///
@@ -818,10 +811,11 @@ struct Array(T)
     }
     do
     {
-        const oldLen = length;
-        const offset = r.end - this.data;
+        const oldLength = length;
+        const after = r.end - this.data;
         const inserted = insertBack(el);
-        bringToFront(this.data[offset .. oldLen], this.data[oldLen .. length]);
+
+        rotate(this.data[after .. oldLength], this.data[oldLength .. length]);
         return inserted;
     }
 
@@ -860,7 +854,7 @@ struct Array(T)
         {
             moveBack(el);
         }
-        bringToFront(this.data[offset .. oldLen], this.data[oldLen .. length]);
+        rotate(this.data[offset .. oldLen], this.data[oldLen .. length]);
 
         return 1;
     }
@@ -916,7 +910,7 @@ struct Array(T)
         {
             moveBack(el);
         }
-        bringToFront(this.data[offset .. oldLen], this.data[oldLen .. length]);
+        rotate(this.data[offset .. oldLen], this.data[oldLen .. length]);
 
         return 1;
     }
@@ -1007,7 +1001,7 @@ struct Array(T)
      */
     ref T opIndexAssign(E : T)(auto ref E value, size_t pos)
     {
-        return opIndex(pos) = value;
+        return opIndex(pos) = forward!value;
     }
 
     /// ditto
@@ -1041,7 +1035,7 @@ struct Array(T)
     }
 
     /// ditto
-    Range opIndexAssign(Range value)
+    Range opIndexAssign()(Range value)
     {
         return opSliceAssign(value, 0, length);
     }
@@ -1335,7 +1329,7 @@ struct Array(T)
     }
 
     /// ditto
-    Range opSliceAssign(Range value, size_t i, size_t j) @trusted
+    Range opSliceAssign()(Range value, size_t i, size_t j) @trusted
     in
     {
         assert(i <= j);
@@ -1555,14 +1549,14 @@ struct Array(T)
 {
     struct MutableEqualsStruct
     {
-        int opEquals(typeof(this) that) @nogc nothrow pure @safe
+        bool opEquals(typeof(this) that) @nogc nothrow pure @safe
         {
             return true;
         }
     }
     struct ConstEqualsStruct
     {
-        int opEquals(const typeof(this) that) const @nogc nothrow pure @safe
+        bool opEquals(const typeof(this) that) const @nogc nothrow pure @safe
         {
             return true;
         }
@@ -1589,15 +1583,10 @@ struct Array(T)
     assert(v7[].equal(v8[]));
 }
 
+// Destructor can destroy empty arrays
 @nogc nothrow pure @safe unittest
 {
-    struct SWithDtor
-    {
-        ~this() @nogc nothrow pure @safe
-        {
-        }
-    }
-    auto v = Array!SWithDtor(); // Destructor can destroy empty arrays.
+    auto v = Array!WithDtor();
 }
 
 @nogc nothrow pure @safe unittest
@@ -1608,7 +1597,6 @@ struct Array(T)
     A a1, a2;
     auto v1 = Array!A([a1, a2]);
 
-    // Issue 232: https://issues.caraus.io/issues/232.
     static assert(is(Array!(A*)));
 }
 
@@ -1693,3 +1681,10 @@ struct Array(T)
     }
     func(array);
 }
+
+// Can have non-copyable elements
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(Array!NonCopyable));
+    static assert(is(typeof({ Array!NonCopyable.init[0] = NonCopyable(); })));
+}

source/tanya/container/buffer.d

@@ -51,7 +51,7 @@ version (unittest)
  *  T = Buffer type.
  */
 struct ReadBuffer(T = ubyte)
-    if (isScalarType!T)
+if (isScalarType!T)
 {
     /// Internal buffer.
     private T[] buffer_;
@@ -66,16 +66,16 @@ struct ReadBuffer(T = ubyte)
     private size_t ring;
 
     /// Available space.
-    private immutable size_t minAvailable = 1024;
+    private size_t minAvailable = 1024;
 
     /// Size by which the buffer will grow.
-    private immutable size_t blockSize = 8192;
+    private size_t blockSize = 8192;
 
     invariant
     {
-        assert(length_ <= buffer_.length);
-        assert(blockSize > 0);
-        assert(minAvailable > 0);
+        assert(this.length_ <= this.buffer_.length);
+        assert(this.blockSize > 0);
+        assert(this.minAvailable > 0);
     }
 
     /**
@@ -89,14 +89,14 @@ struct ReadBuffer(T = ubyte)
      *                 $(D_PSYMBOL free) < $(D_PARAM minAvailable)).
      *  allocator    = Allocator.
      */
-    this(in size_t size,
-         in size_t minAvailable = 1024,
+    this(size_t size,
+         size_t minAvailable = 1024,
          shared Allocator allocator = defaultAllocator) @trusted
     {
         this(allocator);
         this.minAvailable = minAvailable;
         this.blockSize = size;
-        buffer_ = cast(T[]) allocator_.allocate(size * T.sizeof);
+        this.buffer_ = cast(T[]) allocator_.allocate(size * T.sizeof);
     }
 
     /// ditto
@@ -115,7 +115,7 @@ struct ReadBuffer(T = ubyte)
      */
     ~this() @trusted
     {
-        allocator.deallocate(buffer_);
+        allocator.deallocate(this.buffer_);
     }
 
     ///
@@ -131,7 +131,7 @@ struct ReadBuffer(T = ubyte)
      */
     @property size_t capacity() const
     {
-        return buffer_.length;
+        return this.buffer_.length;
     }
 
     /**
@@ -139,7 +139,7 @@ struct ReadBuffer(T = ubyte)
      */
     @property size_t length() const
     {
-        return length_ - start;
+        return this.length_ - start;
     }
 
     /// ditto
@@ -152,7 +152,7 @@ struct ReadBuffer(T = ubyte)
      */
     void clear()
     {
-        start = length_ = ring;
+        start = this.length_ = ring;
     }
 
     /**
@@ -187,10 +187,10 @@ struct ReadBuffer(T = ubyte)
      *
      * Returns: $(D_KEYWORD this).
      */
-    ref ReadBuffer opOpAssign(string op)(in size_t length)
+    ref ReadBuffer opOpAssign(string op)(size_t length)
         if (op == "+")
     {
-        length_ += length;
+        this.length_ += length;
         ring = start;
         return this;
     }
@@ -234,9 +234,9 @@ struct ReadBuffer(T = ubyte)
      *
      * Returns: Array between $(D_PARAM start) and $(D_PARAM end).
      */
-    T[] opSlice(in size_t start, in size_t end)
+    T[] opSlice(size_t start, size_t end)
     {
-        return buffer_[this.start + start .. this.start + end];
+        return this.buffer_[this.start + start .. this.start + end];
     }
 
     /**
@@ -250,23 +250,24 @@ struct ReadBuffer(T = ubyte)
     {
         if (start > 0)
         {
-            auto ret = buffer_[0 .. start];
+            auto ret = this.buffer_[0 .. start];
             ring = 0;
             return ret;
         }
         else
         {
-            if (capacity - length < minAvailable)
+            if (capacity - length < this.minAvailable)
             {
-                void[] buf = buffer_;
-                immutable cap = capacity;
+                void[] buf = this.buffer_;
+                const cap = capacity;
                 () @trusted {
-                    allocator.reallocate(buf, (cap + blockSize) * T.sizeof);
-                    buffer_ = cast(T[]) buf;
+                    allocator.reallocate(buf,
+                                         (cap + this.blockSize) * T.sizeof);
+                    this.buffer_ = cast(T[]) buf;
                 }();
             }
-            ring = length_;
-            return buffer_[length_ .. $];
+            ring = this.length_;
+            return this.buffer_[this.length_ .. $];
         }
     }
 
@@ -310,7 +311,7 @@ struct ReadBuffer(T = ubyte)
  *  T = Buffer type.
  */
 struct WriteBuffer(T = ubyte)
-    if (isScalarType!T)
+if (isScalarType!T)
 {
     /// Internal buffer.
     private T[] buffer_;
@@ -322,16 +323,16 @@ struct WriteBuffer(T = ubyte)
     private size_t ring;
 
     /// Size by which the buffer will grow.
-    private immutable size_t blockSize;
+    private const size_t blockSize;
 
     /// The position of the free area in the buffer.
     private size_t position;
 
     invariant
     {
-        assert(blockSize > 0);
+        assert(this.blockSize > 0);
         // Position can refer to an element outside the buffer if the buffer is full.
-        assert(position <= buffer_.length);
+        assert(this.position <= this.buffer_.length);
     }
 
     /**
@@ -342,7 +343,7 @@ struct WriteBuffer(T = ubyte)
      *
      * Precondition: $(D_INLINECODE size > 0 && allocator !is null)
      */
-    this(in size_t size, shared Allocator allocator = defaultAllocator) @trusted
+    this(size_t size, shared Allocator allocator = defaultAllocator) @trusted
     in
     {
         assert(size > 0);
@@ -350,10 +351,10 @@ struct WriteBuffer(T = ubyte)
     }
     do
     {
-        blockSize = size;
+        this.blockSize = size;
         ring = size - 1;
         allocator_ = allocator;
-        buffer_ = cast(T[]) allocator_.allocate(size * T.sizeof);
+        this.buffer_ = cast(T[]) allocator_.allocate(size * T.sizeof);
     }
 
     @disable this();
@@ -363,7 +364,7 @@ struct WriteBuffer(T = ubyte)
      */
     ~this()
     {
-        allocator.deallocate(buffer_);
+        allocator.deallocate(this.buffer_);
     }
 
     /**
@@ -371,7 +372,7 @@ struct WriteBuffer(T = ubyte)
      */
     @property size_t capacity() const
     {
-        return buffer_.length;
+        return this.buffer_.length;
     }
 
     /**
@@ -384,13 +385,13 @@ struct WriteBuffer(T = ubyte)
      */
     @property size_t length() const
     {
-        if (position > ring || position < start) // Buffer overflowed
+        if (this.position > ring || this.position < start) // Buffer overflowed
         {
             return ring - start + 1;
         }
         else
         {
-            return position - start;
+            return this.position - start;
         }
     }
 
@@ -433,61 +434,62 @@ struct WriteBuffer(T = ubyte)
      * Params:
      *  buffer = Buffer chunk got with $(D_PSYMBOL opIndex).
      */
-    ref WriteBuffer opOpAssign(string op)(in T[] buffer)
+    ref WriteBuffer opOpAssign(string op)(const T[] buffer)
         if (op == "~")
     {
         size_t end, start;
 
-        if (position >= this.start && position <= ring)
+        if (this.position >= this.start && this.position <= ring)
         {
             auto afterRing = ring + 1;
 
-            end = position + buffer.length;
+            end = this.position + buffer.length;
             if (end > afterRing)
             {
                 end = afterRing;
             }
-            start = end - position;
-            buffer_[position .. end] = buffer[0 .. start];
+            start = end - this.position;
+            this.buffer_[this.position .. end] = buffer[0 .. start];
             if (end == afterRing)
             {
-                position = this.start == 0 ? afterRing : 0;
+                this.position = this.start == 0 ? afterRing : 0;
             }
             else
             {
-                position = end;
+                this.position = end;
             }
         }
 
         // Check if we have some free space at the beginning
-        if (start < buffer.length && position < this.start)
+        if (start < buffer.length && this.position < this.start)
         {
-            end = position + buffer.length - start;
+            end = this.position + buffer.length - start;
             if (end > this.start)
             {
                 end = this.start;
             }
-            auto areaEnd = end - position + start;
-            buffer_[position .. end] = buffer[start .. areaEnd];
-            position = end == this.start ? ring + 1 : end - position;
+            auto areaEnd = end - this.position + start;
+            this.buffer_[this.position .. end] = buffer[start .. areaEnd];
+            this.position = end == this.start ? ring + 1 : end - this.position;
             start = areaEnd;
         }
 
         // And if we still haven't found any place, save the rest in the overflow area
         if (start < buffer.length)
         {
-            end = position + buffer.length - start;
+            end = this.position + buffer.length - start;
             if (end > capacity)
             {
-                auto newSize = (end / blockSize * blockSize + blockSize) * T.sizeof;
+                const newSize = end / this.blockSize * this.blockSize
+                              + this.blockSize;
                 () @trusted {
-                    void[] buf = buffer_;
-                    allocator.reallocate(buf, newSize);
-                    buffer_ = cast(T[]) buf;
+                    void[] buf = this.buffer_;
+                    allocator.reallocate(buf, newSize * T.sizeof);
+                    this.buffer_ = cast(T[]) buf;
                 }();
             }
-            buffer_[position .. end] = buffer[start .. $];
-            position = end;
+            this.buffer_[this.position .. end] = buffer[start .. $];
+            this.position = end;
             if (this.start == 0)
             {
                 ring = capacity - 1;
@@ -506,7 +508,7 @@ struct WriteBuffer(T = ubyte)
      *
      * Returns: $(D_KEYWORD this).
      */
-    ref WriteBuffer opOpAssign(string op)(in size_t length)
+    ref WriteBuffer opOpAssign(string op)(size_t length)
         if (op == "+")
     in
     {
@@ -521,42 +523,42 @@ struct WriteBuffer(T = ubyte)
         {
             return this;
         }
-        else if (position <= afterRing)
+        else if (this.position <= afterRing)
         {
             start += length;
-            if (start > 0 && position == afterRing)
+            if (start > 0 && this.position == afterRing)
             {
-                position = oldStart;
+                this.position = oldStart;
             }
         }
         else
         {
-            auto overflow = position - afterRing;
+            auto overflow = this.position - afterRing;
 
             if (overflow > length)
             {
-                immutable afterLength = afterRing + length;
-                buffer_[start .. start + length] = buffer_[afterRing .. afterLength];
-                buffer_[afterRing .. afterLength] = buffer_[afterLength .. position];
-                position -= length;
+                const afterLength = afterRing + length;
+                this.buffer_[start .. start + length] = this.buffer_[afterRing .. afterLength];
+                this.buffer_[afterRing .. afterLength] = this.buffer_[afterLength .. this.position];
+                this.position -= length;
             }
             else if (overflow == length)
             {
-                buffer_[start .. start + overflow] = buffer_[afterRing .. position];
-                position -= overflow;
+                this.buffer_[start .. start + overflow] = this.buffer_[afterRing .. this.position];
+                this.position -= overflow;
             }
             else
             {
-                buffer_[start .. start + overflow] = buffer_[afterRing .. position];
-                position = overflow;
+                this.buffer_[start .. start + overflow] = this.buffer_[afterRing .. this.position];
+                this.position = overflow;
             }
             start += length;
 
-            if (start == position)
+            if (start == this.position)
             {
-                if (position != afterRing)
+                if (this.position != afterRing)
                 {
-                    position = 0;
+                    this.position = 0;
                 }
                 start = 0;
                 ring = capacity - 1;
@@ -596,15 +598,15 @@ struct WriteBuffer(T = ubyte)
      *
      * Returns: A chunk of data buffer.
      */
-    T[] opSlice(in size_t start, in size_t end)
+    T[] opSlice(size_t start, size_t end)
     {
-        if (position > ring || position < start) // Buffer overflowed
+        if (this.position > ring || this.position < start) // Buffer overflowed
         {
-            return buffer_[this.start .. ring + 1 - length + end];
+            return this.buffer_[this.start .. ring + 1 - length + end];
         }
         else
         {
-            return buffer_[this.start .. this.start + end];
+            return this.buffer_[this.start .. this.start + end];
         }
     }
 

source/tanya/container/entry.d

@@ -20,6 +20,7 @@ import tanya.memory.allocator;
 import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.typecons;
+version (unittest) import tanya.test.stub;
 
 package struct SEntry(T)
 {
@@ -59,12 +60,12 @@ package struct Bucket(K, V = void)
     }
     BucketStatus status = BucketStatus.empty;
 
-    this(ref K key)
+    this()(ref K key)
     {
         this.key = key;
     }
 
-    @property void key(ref K key)
+    @property void key()(ref K key)
     {
         this.key() = key;
         this.status = BucketStatus.used;
@@ -82,12 +83,18 @@ package struct Bucket(K, V = void)
         }
     }
 
-    bool opEquals(ref inout(K) key) inout
+    void moveKey(ref K key)
+    {
+        move(key, this.key());
+        this.status = BucketStatus.used;
+    }
+
+    bool opEquals(T)(ref const T key) const
     {
         return this.status == BucketStatus.used && this.key == key;
     }
 
-    bool opEquals(ref inout(typeof(this)) that) inout
+    bool opEquals(ref const(typeof(this)) that) const
     {
         return key == that.key && this.status == that.status;
     }
@@ -164,31 +171,36 @@ package struct HashArray(alias hasher, K, V = void)
         .swap(this.length, data.length);
     }
 
-    void opAssign(ref typeof(this) that)
+    void opAssign()(ref typeof(this) that)
     {
         this.array = that.array;
         this.lengthIndex = that.lengthIndex;
         this.length = that.length;
     }
 
+    @property size_t bucketCount() const
+    {
+        return primes[this.lengthIndex];
+    }
+
     /*
      * Returns bucket position for `hash`. `0` may mean the 0th position or an
      * empty `buckets` array.
      */
-    size_t locateBucket(ref const Key key) const
+    size_t locateBucket(T)(ref const T key) const
     {
-        return this.array.length == 0
-             ? 0
-             : hasher(key) % primes[this.lengthIndex];
+        return this.array.length == 0 ? 0 : hasher(key) % bucketCount;
     }
 
     /*
-     * Inserts a key into an empty or deleted bucket. If the key is
-     * already in there, does nothing. Returns the bucket with the key.
+     * If the key doesn't already exists, returns an empty bucket the key can
+     * be inserted in and adjusts the element count. Otherwise returns the
+     * bucket containing the key.
      */
     ref Bucket insert(ref Key key)
     {
-        while ((this.lengthIndex + 1) != primes.length)
+        const newLengthIndex = this.lengthIndex + 1;
+        if (newLengthIndex != primes.length)
         {
             foreach (ref e; this.array[locateBucket(key) .. $])
             {
@@ -203,17 +215,29 @@ package struct HashArray(alias hasher, K, V = void)
                 }
             }
 
-            if (this.rehashToSize(this.lengthIndex + 1))
+            this.rehashToSize(newLengthIndex);
+        }
+
+        foreach (ref e; this.array[locateBucket(key) .. $])
+        {
+            if (e == key)
             {
-                ++this.lengthIndex;
+                return e;
+            }
+            else if (e.status != BucketStatus.used)
+            {
+                ++this.length;
+                return e;
             }
         }
-        this.array.insertBack(Bucket(key));
+
+        this.array.length = this.array.length + 1;
+        ++this.length;
         return this.array[$ - 1];
     }
 
     // Takes an index in the primes array.
-    bool rehashToSize(const size_t n)
+    void rehashToSize(const size_t n)
     in
     {
         assert(n < primes.length);
@@ -231,15 +255,15 @@ package struct HashArray(alias hasher, K, V = void)
                 {
                     if (e2.status != BucketStatus.used) // Insert the key
                     {
-                        e2 = e1;
+                        .move(e1, e2);
                         continue DataLoop;
                     }
                 }
-                return false; // Rehashing failed.
+                storage.insertBack(.move(e1));
             }
         }
         .move(storage, this.array);
-        return true;
+        this.lengthIndex = n;
     }
 
     void rehash(const size_t n)
@@ -252,9 +276,9 @@ package struct HashArray(alias hasher, K, V = void)
                 break;
             }
         }
-        if (this.rehashToSize(lengthIndex))
+        if (lengthIndex > this.lengthIndex)
         {
-            this.lengthIndex = lengthIndex;
+            this.rehashToSize(lengthIndex);
         }
     }
 
@@ -287,7 +311,7 @@ package struct HashArray(alias hasher, K, V = void)
         return 0;
     }
 
-    bool opBinaryRight(string op : "in")(ref inout(Key) key) inout
+    bool opBinaryRight(string op : "in", T)(ref const T key) const
     {
         foreach (ref e; this.array[locateBucket(key) .. $])
         {
@@ -303,3 +327,13 @@ package struct HashArray(alias hasher, K, V = void)
         return false;
     }
 }
+
+// Can be constructed with non-copyable key/values
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(Bucket!NonCopyable));
+    static assert(is(Bucket!(NonCopyable, NonCopyable)));
+
+    static assert(is(HashArray!((ref NonCopyable) => 0U, NonCopyable)));
+    static assert(is(HashArray!((ref NonCopyable) => 0U, NonCopyable, NonCopyable)));
+}

source/tanya/container/hashtable.d

@@ -14,6 +14,7 @@
  */
 module tanya.container.hashtable;
 
+import tanya.algorithm.mutation;
 import tanya.container.array;
 import tanya.container.entry;
 import tanya.hash.lookup;
@@ -21,6 +22,7 @@ import tanya.memory;
 import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.range.primitive;
+version (unittest) import tanya.test.stub;
 
 /**
  * Bidirectional range whose element type is a tuple of a key and the
@@ -67,7 +69,7 @@ struct Range(T)
         return this.dataRange.empty();
     }
 
-    @property void popFront()
+    void popFront()
     in
     {
         assert(!empty);
@@ -86,7 +88,7 @@ struct Range(T)
         while (!empty && dataRange.front.status != BucketStatus.used);
     }
 
-    @property void popBack()
+    void popBack()
     in
     {
         assert(!empty);
@@ -138,6 +140,236 @@ struct Range(T)
     }
 }
 
+/**
+ * Bidirectional range iterating over the key of a $(D_PSYMBOL HashTable).
+ *
+ * Params:
+ *  T = Type of the internal hash storage.
+ */
+struct ByKey(T)
+{
+    private alias Key = CopyConstness!(T, T.Key);
+    static if (isMutable!T)
+    {
+        private alias DataRange = T.array.Range;
+    }
+    else
+    {
+        private alias DataRange = T.array.ConstRange;
+    }
+    private DataRange dataRange;
+
+    @disable this();
+
+    private this(DataRange dataRange)
+    {
+        while (!dataRange.empty && dataRange.front.status != BucketStatus.used)
+        {
+            dataRange.popFront();
+        }
+        while (!dataRange.empty && dataRange.back.status != BucketStatus.used)
+        {
+            dataRange.popBack();
+        }
+        this.dataRange = dataRange;
+    }
+
+    @property ByKey save()
+    {
+        return this;
+    }
+
+    @property bool empty() const
+    {
+        return this.dataRange.empty();
+    }
+
+    @property void popFront()
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(empty || this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        do
+        {
+            this.dataRange.popFront();
+        }
+        while (!empty && dataRange.front.status != BucketStatus.used);
+    }
+
+    @property void popBack()
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(empty || this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        do
+        {
+            this.dataRange.popBack();
+        }
+        while (!empty && dataRange.back.status != BucketStatus.used);
+    }
+
+    @property ref inout(Key) front() inout
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    do
+    {
+        return this.dataRange.front.key;
+    }
+
+    @property ref inout(Key) back() inout
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        return this.dataRange.back.key;
+    }
+
+    ByKey opIndex()
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+
+    ByKey!(const T) opIndex() const
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+}
+
+/**
+ * Bidirectional range iterating over the key of a $(D_PSYMBOL HashTable).
+ *
+ * Params:
+ *  T = Type of the internal hash storage.
+ */
+struct ByValue(T)
+{
+    private alias Value = CopyConstness!(T, T.Value);
+    static if (isMutable!T)
+    {
+        private alias DataRange = T.array.Range;
+    }
+    else
+    {
+        private alias DataRange = T.array.ConstRange;
+    }
+    private DataRange dataRange;
+
+    @disable this();
+
+    private this(DataRange dataRange)
+    {
+        while (!dataRange.empty && dataRange.front.status != BucketStatus.used)
+        {
+            dataRange.popFront();
+        }
+        while (!dataRange.empty && dataRange.back.status != BucketStatus.used)
+        {
+            dataRange.popBack();
+        }
+        this.dataRange = dataRange;
+    }
+
+    @property ByValue save()
+    {
+        return this;
+    }
+
+    @property bool empty() const
+    {
+        return this.dataRange.empty();
+    }
+
+    @property void popFront()
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(empty || this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        do
+        {
+            this.dataRange.popFront();
+        }
+        while (!empty && dataRange.front.status != BucketStatus.used);
+    }
+
+    @property void popBack()
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    out
+    {
+        assert(empty || this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        do
+        {
+            this.dataRange.popBack();
+        }
+        while (!empty && dataRange.back.status != BucketStatus.used);
+    }
+
+    @property ref inout(Value) front() inout
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.front.status == BucketStatus.used);
+    }
+    do
+    {
+        return this.dataRange.front.kv.value;
+    }
+
+    @property ref inout(Value) back() inout
+    in
+    {
+        assert(!empty);
+        assert(this.dataRange.back.status == BucketStatus.used);
+    }
+    do
+    {
+        return this.dataRange.back.kv.value;
+    }
+
+    ByValue opIndex()
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+
+    ByValue!(const T) opIndex() const
+    {
+        return typeof(return)(this.dataRange[]);
+    }
+}
+
 /**
  * Hash table is a data structure that stores pairs of keys and values without
  * any particular order.
@@ -155,7 +387,7 @@ struct Range(T)
  *  hasher = Hash function for $(D_PARAM Key).
  */
 struct HashTable(Key, Value, alias hasher = hash)
-if (is(typeof(hasher(Key.init)) == size_t))
+if (isHashFunction!(hasher, Key))
 {
     private alias HashArray = .HashArray!(hasher, Key, Value);
     private alias Buckets = HashArray.Buckets;
@@ -171,11 +403,18 @@ if (is(typeof(hasher(Key.init)) == size_t))
     /// ditto
     alias ConstRange = .Range!(const HashArray);
 
+    /// ditto
+    alias ByKey = .ByKey!(const HashArray);
+
+    /// ditto
+    alias ByValue = .ByValue!HashArray;
+
+    /// ditto
+    alias ConstByValue = .ByValue!(const HashArray);
+
     invariant
     {
         assert(this.data.lengthIndex < primes.length);
-        assert(this.data.array.length == 0
-            || this.data.array.length == primes[this.data.lengthIndex]);
     }
 
     /**
@@ -440,6 +679,23 @@ if (is(typeof(hasher(Key.init)) == size_t))
         assert(hashTable.empty);
     }
 
+    /**
+     * Returns current bucket count in the container.
+     *
+     * Bucket count equals to the number of the elements can be saved in the
+     * container in the best case scenario for key distribution, i.d. every key
+     * has a unique hash value. In a worse case the bucket count can be less
+     * than the number of elements stored in the container.
+     *
+     * Returns: Current bucket count.
+     *
+     * See_Also: $(D_PSYMBOL rehash).
+     */
+    @property size_t bucketCount() const
+    {
+        return this.data.bucketCount;
+    }
+
     /// The maximum number of buckets the container can have.
     enum size_t maxBucketCount = primes[$ - 1];
 
@@ -453,14 +709,28 @@ if (is(typeof(hasher(Key.init)) == size_t))
      *
      * Returns: Just inserted element.
      */
-    ref Value opIndexAssign(Value value, Key key)
+    ref Value opIndexAssign()(auto ref Value value, auto ref Key key)
     {
         auto e = ((ref v) @trusted => &this.data.insert(v))(key);
         if (e.status != BucketStatus.used)
         {
-            e.key = key;
+            static if (__traits(isRef, key))
+            {
+                e.key = key;
+            }
+            else
+            {
+                e.moveKey(key);
+            }
+        }
+        static if (__traits(isRef, value))
+        {
+            return e.kv.value = value;
+        }
+        else
+        {
+            return e.kv.value = move(value);
         }
-        return e.kv.value = value;
     }
 
     ///
@@ -490,7 +760,7 @@ if (is(typeof(hasher(Key.init)) == size_t))
      *
      * Returns: The number of the inserted elements with a unique key.
      */
-    size_t insert(KeyValue keyValue)
+    size_t insert()(ref KeyValue keyValue)
     {
         auto e = ((ref v) @trusted => &this.data.insert(v))(keyValue.key);
         size_t inserted;
@@ -503,6 +773,20 @@ if (is(typeof(hasher(Key.init)) == size_t))
         return inserted;
     }
 
+    /// ditto
+    size_t insert()(KeyValue keyValue)
+    {
+        auto e = ((ref v) @trusted => &this.data.insert(v))(keyValue.key);
+        size_t inserted;
+        if (e.status != BucketStatus.used)
+        {
+            e.moveKey(keyValue.key);
+            inserted = 1;
+        }
+        move(keyValue.value, e.kv.value);
+        return inserted;
+    }
+
     ///
     @nogc nothrow pure @safe unittest
     {
@@ -557,13 +841,15 @@ if (is(typeof(hasher(Key.init)) == size_t))
      * Find the element with the key $(D_PARAM key).
      *
      * Params:
+     *  T   = Type comparable with the key type, used for the lookup.
      *  key = The key to be find.
      *
      * Returns: The value associated with $(D_PARAM key).
      *
      * Precondition: Element with $(D_PARAM key) is in this hash table.
      */
-    ref Value opIndex(Key key)
+    ref Value opIndex(T)(auto ref const T key)
+    if (ifTestable!(T, a => Key.init == a))
     {
         const code = this.data.locateBucket(key);
 
@@ -619,12 +905,14 @@ if (is(typeof(hasher(Key.init)) == size_t))
      * Looks for $(D_PARAM key) in this hash table.
      *
      * Params:
+     *  T   = Type comparable with the key type, used for the lookup.
      *  key = The key to look for.
      *
      * Returns: $(D_KEYWORD true) if $(D_PARAM key) exists in the hash table,
      *          $(D_KEYWORD false) otherwise.
      */
-    bool opBinaryRight(string op : "in")(auto ref inout(Key) key) inout
+    bool opBinaryRight(string op : "in", T)(auto ref const T key) const
+    if (ifTestable!(T, a => Key.init == a))
     {
         return key in this.data;
     }
@@ -645,18 +933,15 @@ if (is(typeof(hasher(Key.init)) == size_t))
      * Sets the number of buckets in the container to at least $(D_PARAM n)
      * and rearranges all the elements according to their hash values.
      *
-     * If $(D_PARAM n) is greater than the current $(D_PSYMBOL capacity)
+     * If $(D_PARAM n) is greater than the current $(D_PSYMBOL bucketCount)
      * and lower than or equal to $(D_PSYMBOL maxBucketCount), a rehash is
      * forced.
      *
      * If $(D_PARAM n) is greater than $(D_PSYMBOL maxBucketCount),
      * $(D_PSYMBOL maxBucketCount) is used instead as a new number of buckets.
      *
-     * If $(D_PARAM n) is equal to the current $(D_PSYMBOL capacity), rehashing
-     * is forced without resizing the container.
-     *
-     * If $(D_PARAM n) is lower than the current $(D_PSYMBOL capacity), the
-     * function may have no effect.
+     * If $(D_PARAM n) is less than or equal to the current
+     * $(D_PSYMBOL bucketCount), the function may have no effect.
      *
      * Rehashing is automatically performed whenever the container needs space
      * to insert new elements.
@@ -697,6 +982,86 @@ if (is(typeof(hasher(Key.init)) == size_t))
         assert(hashTable[].front == hashTable.KeyValue("Iguanodon", 9));
         assert(hashTable[].back == hashTable.KeyValue("Iguanodon", 9));
     }
+
+    /**
+     * Returns a bidirectional range that iterats over the keys of this
+     * $(D_PSYMBOL HashTable).
+     *
+     * This function always returns a $(D_KEYWORD const) range, since changing
+     * a key of a hash table would probably change its hash value and require
+     * rehashing.
+     *
+     * Returns: $(D_KEYWORD const) bidirectional range that iterates over the
+     *          keys of the container.
+     *
+     * See_Also: $(D_PSYMBOL byValue).
+     */
+    ByKey byKey() const
+    {
+        return typeof(return)(this.data.array[]);
+    }
+
+    ///
+    @nogc nothrow pure @safe unittest
+    {
+        HashTable!(string, int) hashTable;
+        hashTable["one"] = 1;
+        hashTable["two"] = 2;
+
+        auto byKey = hashTable.byKey();
+        assert(!byKey.empty);
+
+        assert(byKey.front == "one" || byKey.front == "two");
+        assert(byKey.back == "one" || byKey.back == "two");
+        assert(byKey.front != byKey.back);
+
+        byKey.popFront();
+        assert(byKey.front == byKey.back);
+
+        byKey.popBack();
+        assert(byKey.empty);
+    }
+
+    /**
+     * Returns a bidirectional range that iterats over the values of this
+     * $(D_PSYMBOL HashTable).
+     *
+     * Returns: A bidirectional range that iterates over the values of the
+     *          container.
+     *
+     * See_Also: $(D_PSYMBOL byKey).
+     */
+    ByValue byValue()
+    {
+        return typeof(return)(this.data.array[]);
+    }
+
+    /// ditto
+    ConstByValue byValue() const
+    {
+        return typeof(return)(this.data.array[]);
+    }
+
+    ///
+    @nogc nothrow pure @safe unittest
+    {
+        HashTable!(string, int) hashTable;
+        hashTable["one"] = 1;
+        hashTable["two"] = 2;
+
+        auto byValue = hashTable.byValue();
+        assert(!byValue.empty);
+
+        assert(byValue.front == 1 || byValue.front == 2);
+        assert(byValue.back == 1 || byValue.back == 2);
+        assert(byValue.front != byValue.back);
+
+        byValue.popFront();
+        assert(byValue.front == byValue.back);
+
+        byValue.popBack();
+        assert(byValue.empty);
+    }
 }
 
 @nogc nothrow pure @safe unittest
@@ -727,6 +1092,9 @@ if (is(typeof(hasher(Key.init)) == size_t))
     static assert(is(HashTable!(string, int) a));
     static assert(is(const HashTable!(string, int)));
     static assert(isForwardRange!(HashTable!(string, int).Range));
+
+    static assert(is(HashTable!(int, int, (ref const int) => size_t.init)));
+    static assert(is(HashTable!(int, int, (int) => size_t.init)));
 }
 
 // Constructs by reference
@@ -773,3 +1141,73 @@ if (is(typeof(hasher(Key.init)) == size_t))
     }
     testFunc(hashTable);
 }
+
+// Issue 53: https://github.com/caraus-ecms/tanya/issues/53
+@nogc nothrow pure @safe unittest
+{
+    {
+        HashTable!(uint, uint) hashTable;
+        foreach (uint i; 0 .. 14)
+        {
+            hashTable[i + 1] = i;
+        }
+        assert(hashTable.length == 14);
+    }
+    {
+        HashTable!(int, int) hashtable;
+
+        hashtable[1194250162] = 3;
+        hashtable[-1131293824] = 6;
+        hashtable[838100082] = 9;
+
+        hashtable.rehash(11);
+
+        assert(hashtable[-1131293824] == 6);
+    }
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static struct String
+    {
+        bool opEquals(string) const @nogc nothrow pure @safe
+        {
+            return true;
+        }
+
+        bool opEquals(ref const string) const @nogc nothrow pure @safe
+        {
+            return true;
+        }
+
+        bool opEquals(String) const @nogc nothrow pure @safe
+        {
+            return true;
+        }
+
+        bool opEquals(ref const String) const @nogc nothrow pure @safe
+        {
+            return true;
+        }
+
+        size_t toHash() const @nogc nothrow pure @safe
+        {
+            return 0;
+        }
+    }
+    static assert(is(typeof("asdf" in HashTable!(String, int)())));
+    static assert(is(typeof(HashTable!(String, int)()["asdf"])));
+}
+
+// Can have non-copyable keys and elements
+@nogc nothrow pure @safe unittest
+{
+    @NonCopyable @Hashable
+    static struct S
+    {
+        mixin StructStub;
+    }
+    static assert(is(HashTable!(S, int)));
+    static assert(is(HashTable!(int, S)));
+    static assert(is(HashTable!(S, S)));
+}

source/tanya/container/list.d

@@ -15,8 +15,6 @@
  */
 module tanya.container.list;
 
-import std.algorithm.comparison : equal;
-import std.algorithm.searching;
 import tanya.algorithm.comparison;
 import tanya.algorithm.mutation;
 import tanya.container.entry;
@@ -25,6 +23,7 @@ import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.range.array;
 import tanya.range.primitive;
+version (unittest) import tanya.test.stub;
 
 /**
  * Forward range for the $(D_PSYMBOL SList).
@@ -157,8 +156,9 @@ struct SList(T)
      *  init      = Initial value to fill the list with.
      *  allocator = Allocator.
      */
-    this(size_t len, T init, shared Allocator allocator = defaultAllocator)
-    @trusted
+    this()(size_t len,
+           auto ref T init,
+           shared Allocator allocator = defaultAllocator)
     {
         this(allocator);
         if (len == 0)
@@ -178,21 +178,30 @@ struct SList(T)
     @nogc nothrow pure @safe unittest
     {
         auto l = SList!int(2, 3);
-        assert(l.length == 2);
         assert(l.front == 3);
     }
 
     /// ditto
     this(size_t len, shared Allocator allocator = defaultAllocator)
     {
-        this(len, T.init, allocator);
+        this(allocator);
+        if (len == 0)
+        {
+            return;
+        }
+
+        Entry* next = this.head = allocator.make!Entry();
+        foreach (i; 1 .. len)
+        {
+            next.next = allocator.make!Entry();
+            next = next.next;
+        }
     }
 
     ///
     @nogc nothrow pure @safe unittest
     {
         auto l = SList!int(2);
-        assert(l.length == 2);
         assert(l.front == 0);
     }
 
@@ -275,14 +284,18 @@ struct SList(T)
         clear();
     }
 
-    /**
-     * Copies the list.
-     */
-    this(this)
+    static if (isCopyable!T)
     {
-        auto list = typeof(this)(this[], this.allocator);
-        this.head = list.head;
-        list.head = null;
+        this(this)
+        {
+            auto list = typeof(this)(this[], this.allocator);
+            this.head = list.head;
+            list.head = null;
+        }
+    }
+    else
+    {
+        @disable this(this);
     }
 
     ///
@@ -432,7 +445,6 @@ struct SList(T)
         assert(l2.front == 25);
 
         l2.insertFront(l1[]);
-        assert(l2.length == 5);
         assert(l2.front == 9);
     }
 
@@ -517,7 +529,7 @@ struct SList(T)
     }
 
     /// ditto
-    size_t insertBefore(Range r, ref T el) @trusted
+    size_t insertBefore()(Range r, ref T el) @trusted
     in
     {
         assert(checkRangeBelonging(r));
@@ -566,12 +578,6 @@ struct SList(T)
         assert(l1 == l2);
     }
 
-    deprecated
-    @property size_t length() const
-    {
-        return count(this[]);
-    }
-
     /**
      * Comparison for equality.
      *
@@ -583,7 +589,7 @@ struct SList(T)
      */
     bool opEquals()(auto ref typeof(this) that) inout
     {
-        return equal(this[], that[]);
+        return equal(opIndex(), that[]);
     }
 
     ///
@@ -1131,8 +1137,9 @@ struct DList(T)
      *  init      = Initial value to fill the list with.
      *  allocator = Allocator.
      */
-    this(size_t len, T init, shared Allocator allocator = defaultAllocator)
-    @trusted
+    this()(size_t len,
+           auto ref T init,
+           shared Allocator allocator = defaultAllocator)
     {
         this(allocator);
         if (len == 0)
@@ -1154,7 +1161,6 @@ struct DList(T)
     @nogc nothrow pure @safe unittest
     {
         auto l = DList!int(2, 3);
-        assert(l.length == 2);
         assert(l.front == 3);
         assert(l.back == 3);
     }
@@ -1162,14 +1168,26 @@ struct DList(T)
     /// ditto
     this(size_t len, shared Allocator allocator = defaultAllocator)
     {
-        this(len, T.init, allocator);
+        this(allocator);
+        if (len == 0)
+        {
+            return;
+        }
+
+        Entry* next = this.head = allocator.make!Entry();
+        foreach (i; 1 .. len)
+        {
+            next.next = allocator.make!Entry();
+            next.next.prev = next;
+            next = next.next;
+        }
+        this.tail = next;
     }
 
     ///
     @nogc nothrow pure @safe unittest
     {
         auto l = DList!int(2);
-        assert(l.length == 2);
         assert(l.front == 0);
     }
 
@@ -1255,15 +1273,19 @@ struct DList(T)
         clear();
     }
 
-    /**
-     * Copies the list.
-     */
-    this(this)
+    static if (isCopyable!T)
     {
-        auto list = typeof(this)(this[], this.allocator);
-        this.head = list.head;
-        this.tail = list.tail;
-        list.head = list .tail = null;
+        this(this)
+        {
+            auto list = typeof(this)(this[], this.allocator);
+            this.head = list.head;
+            this.tail = list.tail;
+            list.head = list .tail = null;
+        }
+    }
+    else
+    {
+        @disable this(this);
     }
 
     ///
@@ -1480,7 +1502,6 @@ struct DList(T)
         assert(l2.back == 15);
 
         l2.insertFront(l1[]);
-        assert(l2.length == 5);
         assert(l2.front == 9);
         assert(l2.back == 15);
     }
@@ -1600,7 +1621,6 @@ struct DList(T)
         assert(l2.back == 15);
 
         l2.insertBack(l1[]);
-        assert(l2.length == 5);
         assert(l2.back == 9);
     }
 
@@ -1656,7 +1676,7 @@ struct DList(T)
     }
 
     /// ditto
-    size_t insertBefore(Range r, ref T el) @trusted
+    size_t insertBefore()(Range r, ref T el) @trusted
     in
     {
         assert(checkRangeBelonging(r));
@@ -1773,7 +1793,7 @@ struct DList(T)
     }
 
     /// ditto
-    size_t insertAfter(Range r, ref T el) @trusted
+    size_t insertAfter()(Range r, ref T el) @trusted
     in
     {
         assert(checkRangeBelonging(r));
@@ -1855,12 +1875,6 @@ struct DList(T)
         return insertAfter!(T[])(r, el[]);
     }
 
-    deprecated
-    @property size_t length() const
-    {
-        return count(this[]);
-    }
-
     /**
      * Comparison for equality.
      *
@@ -2354,7 +2368,6 @@ struct DList(T)
     l.insertAfter(l[], 234);
     assert(l.front == 234);
     assert(l.back == 234);
-    assert(l.length == 1);
 }
 
 @nogc nothrow pure @safe unittest
@@ -2377,3 +2390,10 @@ struct DList(T)
     assert(!l1.remove(r).empty);
     assert(l1 == l2);
 }
+
+// Can have non-copyable elements
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(SList!NonCopyable));
+    static assert(is(DList!NonCopyable));
+}

source/tanya/container/package.d

@@ -20,26 +20,3 @@ public import tanya.container.hashtable;
 public import tanya.container.list;
 public import tanya.container.set;
 public import tanya.container.string;
-
-/**
- * Thrown if $(D_PSYMBOL Set) cannot insert a new element because the container
- * is full.
- */
-deprecated
-class HashContainerFullException : Exception
-{
-    /**
-     * Params:
-     *  msg  = The message for the exception.
-     *  file = The file where the exception occurred.
-     *  line = The line number where the exception occurred.
-     *  next = The previous exception in the chain of exceptions, if any.
-     */
-    this(string msg,
-         string file = __FILE__,
-         size_t line = __LINE__,
-         Throwable next = null) @nogc nothrow pure @safe
-    {
-        super(msg, file, line, next);
-    }
-}

source/tanya/container/set.d

@@ -15,7 +15,6 @@
  */
 module tanya.container.set;
 
-import tanya.algorithm.mutation;
 import tanya.container.array;
 import tanya.container.entry;
 import tanya.hash.lookup;
@@ -23,6 +22,7 @@ import tanya.memory;
 import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.range.primitive;
+version (unittest) import tanya.test.stub;
 
 /**
  * Bidirectional range that iterates over the $(D_PSYMBOL Set)'s values.
@@ -68,7 +68,7 @@ struct Range(T)
         return this.dataRange.empty();
     }
 
-    @property void popFront()
+    void popFront()
     in
     {
         assert(!empty);
@@ -87,7 +87,7 @@ struct Range(T)
         while (!empty && dataRange.front.status != BucketStatus.used);
     }
 
-    @property void popBack()
+    void popBack()
     in
     {
         assert(!empty);
@@ -155,7 +155,7 @@ struct Range(T)
  *  hasher = Hash function for $(D_PARAM T).
  */
 struct Set(T, alias hasher = hash)
-if (is(typeof(hasher(T.init)) == size_t))
+if (isHashFunction!(hasher, T))
 {
     private alias HashArray = .HashArray!(hasher, T);
     private alias Buckets = HashArray.Buckets;
@@ -432,6 +432,23 @@ if (is(typeof(hasher(T.init)) == size_t))
         assert(set.empty);
     }
 
+    /**
+     * Returns current bucket count in the container.
+     *
+     * Bucket count equals to the number of the elements can be saved in the
+     * container in the best case scenario for key distribution, i.d. every key
+     * has a unique hash value. In a worse case the bucket count can be less
+     * than the number of elements stored in the container.
+     *
+     * Returns: Current bucket count.
+     *
+     * See_Also: $(D_PSYMBOL rehash).
+     */
+    @property size_t bucketCount() const
+    {
+        return this.data.bucketCount;
+    }
+
     /// The maximum number of buckets the container can have.
     enum size_t maxBucketCount = primes[$ - 1];
 
@@ -443,7 +460,18 @@ if (is(typeof(hasher(T.init)) == size_t))
      *
      * Returns: Amount of new elements inserted.
      */
-    size_t insert(T value)
+    size_t insert()(ref T value)
+    {
+        auto e = ((ref v) @trusted => &this.data.insert(v))(value);
+        if (e.status != BucketStatus.used)
+        {
+            e.moveKey(value);
+            return 1;
+        }
+        return 0;
+    }
+
+    size_t insert()(T value)
     {
         auto e = ((ref v) @trusted => &this.data.insert(v))(value);
         if (e.status != BucketStatus.used)
@@ -534,12 +562,14 @@ if (is(typeof(hasher(T.init)) == size_t))
      * $(D_KEYWORD in) operator.
      *
      * Params:
+     *  U     = Type comparable with the element type, used for the lookup.
      *  value = Element to be searched for.
      *
      * Returns: $(D_KEYWORD true) if the given element exists in the container,
      *          $(D_KEYWORD false) otherwise.
      */
-    bool opBinaryRight(string op : "in")(auto ref inout(T) value) inout
+    bool opBinaryRight(string op : "in", U)(auto ref const U value) const
+    if (ifTestable!(U, a => T.init == a))
     {
         return value in this.data;
     }
@@ -559,18 +589,15 @@ if (is(typeof(hasher(T.init)) == size_t))
      * Sets the number of buckets in the container to at least $(D_PARAM n)
      * and rearranges all the elements according to their hash values.
      *
-     * If $(D_PARAM n) is greater than the current $(D_PSYMBOL capacity)
+     * If $(D_PARAM n) is greater than the current $(D_PSYMBOL bucketCount)
      * and lower than or equal to $(D_PSYMBOL maxBucketCount), a rehash is
      * forced.
      *
      * If $(D_PARAM n) is greater than $(D_PSYMBOL maxBucketCount),
      * $(D_PSYMBOL maxBucketCount) is used instead as a new number of buckets.
      *
-     * If $(D_PARAM n) is equal to the current $(D_PSYMBOL capacity), rehashing
-     * is forced without resizing the container.
-     *
-     * If $(D_PARAM n) is lower than the current $(D_PSYMBOL capacity), the
-     * function may have no effect.
+     * If $(D_PARAM n) is less than or equal to the current
+     * $(D_PSYMBOL bucketCount), the function may have no effect.
      *
      * Rehashing is automatically performed whenever the container needs space
      * to insert new elements.
@@ -741,3 +768,20 @@ if (is(typeof(hasher(T.init)) == size_t))
     }
     testFunc(set);
 }
+
+// Hasher can take argument by ref
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(Set!(int, (const ref x) => cast(size_t) x)));
+}
+
+// Can have non-copyable elements
+@nogc nothrow pure @safe unittest
+{
+    @NonCopyable @Hashable
+    static struct S
+    {
+        mixin StructStub;
+    }
+    static assert(is(Set!S));
+}

source/tanya/container/string.d

@@ -26,11 +26,9 @@
  */
 module tanya.container.string;
 
-import std.algorithm.comparison : cmp, equal;
-import std.algorithm.mutation : bringToFront, copy;
-import std.algorithm.searching;
 import tanya.algorithm.comparison;
 import tanya.algorithm.mutation;
+import tanya.hash.lookup;
 import tanya.memory;
 import tanya.meta.trait;
 import tanya.meta.transform;
@@ -499,7 +497,7 @@ struct String
         }
     }
 
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String(0, 'K');
         assert(s.length == 0);
@@ -579,16 +577,10 @@ struct String
      * Params:
      *  chr = The character should be inserted.
      *
-     * Returns: The number of bytes inserted.
-     *
-     * Throws: $(D_PSYMBOL UTFException).
+     * Returns: The number of bytes inserted (1).
      */
-    size_t insertBack(const char chr) @nogc pure @trusted
+    size_t insertBack(char chr) @nogc nothrow pure @trusted
     {
-        if ((chr & 0x80) != 0)
-        {
-            throw defaultAllocator.make!UTFException("Invalid UTF-8 character");
-        }
         reserve(length + 1);
 
         *(data + length) = chr;
@@ -652,8 +644,6 @@ struct String
      *  str = String should be inserted.
      *
      * Returns: The number of bytes inserted.
-     *
-     * Throws: $(D_PSYMBOL UTFException).
      */
     size_t insertBack(R)(R str) @trusted
     if (!isInfinite!R
@@ -673,46 +663,18 @@ struct String
             this.length_ = size;
             return str.length;
         }
+        else static if (isInstanceOf!(ByCodeUnit, R))
+        {
+            str.get.copy(this.data[length .. size]);
+            this.length_ = size;
+            return str.length;
+        }
         else
         {
             size_t insertedLength;
-            while (!str.empty)
+            foreach (c; str)
             {
-                ubyte expectedLength;
-                if ((str.front & 0x80) == 0x00)
-                {
-                    expectedLength = 1;
-                }
-                else if ((str.front & 0xe0) == 0xc0)
-                {
-                    expectedLength = 2;
-                }
-                else if ((str.front & 0xf0) == 0xe0)
-                {
-                    expectedLength = 3;
-                }
-                else if ((str.front & 0xf8) == 0xf0)
-                {
-                    expectedLength = 4;
-                }
-                else
-                {
-                    throw defaultAllocator.make!UTFException("Invalid UTF-8 sequeunce");
-                }
-                size = length + expectedLength;
-                reserve(size);
-
-                for (; expectedLength > 0; --expectedLength)
-                {
-                    if (str.empty)
-                    {
-                        throw defaultAllocator.make!UTFException("Invalid UTF-8 sequeunce");
-                    }
-                    *(data + length) = str.front;
-                    str.popFront();
-                }
-                insertedLength += expectedLength;
-                this.length_ = size;
+                insertedLength += insertBack(c);
             }
             return insertedLength;
         }
@@ -828,7 +790,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         String s;
         assert(s.capacity == 0);
@@ -869,7 +831,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Die Alten lasen laut.");
         assert(s.capacity == 21);
@@ -894,7 +856,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("In allem Schreiben ist Schamlosigkeit.");
         assert(s.capacity == 38);
@@ -991,7 +953,7 @@ struct String
      *
      * Returns: Null-terminated string.
      */
-    const(char)* toStringz() @nogc nothrow pure
+    const(char)* toStringz() @nogc nothrow pure @system
     {
         reserve(length + 1);
         this.data[length] = '\0';
@@ -999,7 +961,7 @@ struct String
     }
 
     ///
-    @nogc pure unittest
+    @nogc nothrow pure @system unittest
     {
         auto s = String("C string.");
         assert(s.toStringz()[0] == 'C');
@@ -1018,7 +980,7 @@ struct String
     alias opDollar = length;
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Piscis primuin a capite foetat.");
         assert(s.length == 31);
@@ -1044,7 +1006,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Alea iacta est.");
         assert(s[0] == 'A');
@@ -1067,7 +1029,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Plutarchus");
         auto r = s[];
@@ -1086,7 +1048,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = const String("Was ich vermag, soll gern geschehen. Goethe");
         auto r1 = s[];
@@ -1162,7 +1124,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         String s;
         assert(s.empty);
@@ -1207,7 +1169,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Vladimir Soloviev");
         auto r = s[9 .. $];
@@ -1271,7 +1233,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Черная, потом пропахшая выть!");
         s = String("Как мне тебя не ласкать, не любить?");
@@ -1299,10 +1261,11 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Оловом светится лужная голь...");
         s = "Грустная песня, ты - русская боль.";
+        assert(s == "Грустная песня, ты - русская боль.");
     }
 
     /**
@@ -1318,33 +1281,33 @@ struct String
     int opCmp(S)(auto ref S that) const @trusted
     if (is(Unqual!S == String))
     {
-        return cmp(this.data[0 .. length], that.data[0 .. that.length]);
+        return compare(this.data[0 .. length], that.data[0 .. that.length]);
     }
 
     /// ditto
     int opCmp(S)(ByCodeUnit!S that) const @trusted
     if (is(Unqual!S == char))
     {
-        return cmp(this.data[0 .. length],
-                   that.begin[0 .. that.end - that.begin]);
+        return compare(this.data[0 .. length],
+                       that.begin[0 .. that.end - that.begin]);
     }
 
     /// ditto
     int opCmp(S)(ByCodePoint!S that) const @trusted
     if (is(Unqual!S == char))
     {
-        return cmp(this.data[0 .. length],
-                   that.begin[0 .. that.end - that.begin]);
+        return compare(this.data[0 .. length],
+                       that.begin[0 .. that.end - that.begin]);
     }
 
     /// ditto
     int opCmp()(const char[] that) const @trusted
     {
-        return cmp(this.data[0 .. length], that);
+        return compare(this.data[0 .. length], that);
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         assert(String("Голубая кофта.") < String("Синие глаза."));
         assert(String("Никакой я правды") < String("милой не сказал")[]);
@@ -1397,7 +1360,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         assert(String("Милая спросила:") != String("Крутит ли метель?"));
         assert(String("Затопить бы печку,") != String("постелить постель.")[]);
@@ -1430,7 +1393,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("alea iacta est.");
 
@@ -1455,7 +1418,7 @@ struct String
         return opSliceAssign(value, 0, length);
     }
 
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s1 = String("Buttercup");
         auto s2 = String("Cap");
@@ -1469,7 +1432,7 @@ struct String
         return opSliceAssign(value, 0, length);
     }
 
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s1 = String("Wow");
         s1[] = 'a';
@@ -1482,7 +1445,7 @@ struct String
         return opSliceAssign(value, 0, length);
     }
 
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s1 = String("ö");
         s1[] = "oe";
@@ -1520,6 +1483,8 @@ struct String
     ///
     @nogc pure @safe unittest
     {
+        import tanya.algorithm.searching : count;
+
         auto s = String("Из пословицы слова не выкинешь.");
 
         assert(s.remove(s[5 .. 24]).length == 33);
@@ -1565,16 +1530,15 @@ struct String
     do
     {
         const oldLength = length;
-        const rangeEnd = r.end - this.data;
+        const after = r.end - this.data;
         const inserted = insertBack(el);
-        auto containerEnd = this.data + oldLength;
-        bringToFront(ByCodeUnit!char(this, this.data + rangeEnd, containerEnd),
-                     ByCodeUnit!char(this, containerEnd, this.data + length));
+
+        rotate(this.data[after .. oldLength], this.data[oldLength .. length]);
         return inserted;
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Казнить нельзя помиловать.");
         s.insertAfter(s[0 .. 27], ",");
@@ -1603,7 +1567,7 @@ struct String
     }
 
     ///
-    @nogc pure @safe unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Казнить нельзя помиловать.");
         s.insertBefore(s[27 .. $], ",");
@@ -1614,11 +1578,21 @@ struct String
         assert(s == "Казнить, нельзя помиловать.");
     }
 
+    /**
+     * Calculates the hash value for the string.
+     *
+     * Returns: Hash value for the string.
+     */
+    size_t toHash() const @nogc nothrow pure @safe
+    {
+        return hash(get);
+    }
+
     mixin DefaultAllocator;
 }
 
-// Postblit works.
-@nogc pure @safe unittest
+// Postblit works
+@nogc nothrow pure @safe unittest
 {
     void internFunc(String arg)
     {
@@ -1637,7 +1611,7 @@ struct String
     topFunc(String("asdf"));
 }
 
-// Const range produces mutable ranges.
+// Const range produces mutable ranges
 @nogc pure @safe unittest
 {
     auto s = const String("И снизу лед, и сверху - маюсь между.");
@@ -1663,7 +1637,7 @@ struct String
     }
 }
 
-// Can pop multibyte characters.
+// Can pop multibyte characters
 @nogc pure @safe unittest
 {
     auto s = String("\U00024B62\U00002260");
@@ -1680,3 +1654,12 @@ struct String
     s[$ - 3] = 0xf0;
     assertThrown!UTFException(&(range.popFront));
 }
+
+// Inserts own char range correctly
+@nogc nothrow pure @safe unittest
+{
+    auto s1 = String(`ü`);
+    String s2;
+    s2.insertBack(s1[]);
+    assert(s1 == s2);
+}

source/tanya/conv.d

@@ -5,7 +5,7 @@
 /**
  * This module provides functions for converting between different types.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2019.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -14,16 +14,20 @@
  */
 module tanya.conv;
 
+import tanya.algorithm.mutation;
 import tanya.container.string;
 import tanya.format;
 import tanya.memory;
 import tanya.memory.op;
 import tanya.meta.trait;
 import tanya.meta.transform;
+import tanya.range.array;
+import tanya.range.primitive;
 
 version (unittest)
 {
     import tanya.test.assertion;
+    import tanya.test.stub;
 }
 
 /**
@@ -58,15 +62,8 @@ version (unittest)
  */
 T emplace(T, U, Args...)(void[] memory, U outer, auto ref Args args)
 if (!isAbstractClass!T && isInnerClass!T && is(typeof(T.outer) == U))
-in
-{
-    assert(memory.length >= stateSize!T);
-}
-out (result)
-{
-    assert(memory.ptr is (() @trusted => cast(void*) result)());
-}
-do
+in (memory.length >= stateSize!T)
+out (result; memory.ptr is (() @trusted => cast(void*) result)())
 {
     copy(typeid(T).initializer, memory);
 
@@ -84,15 +81,8 @@ do
 /// ditto
 T emplace(T, Args...)(void[] memory, auto ref Args args)
 if (is(T == class) && !isAbstractClass!T && !isInnerClass!T)
-in
-{
-    assert(memory.length == stateSize!T);
-}
-out (result)
-{
-    assert(memory.ptr is (() @trusted => cast(void*) result)());
-}
-do
+in (memory.length == stateSize!T)
+out (result; memory.ptr is (() @trusted => cast(void*) result)())
 {
     copy(typeid(T).initializer, memory);
 
@@ -137,15 +127,8 @@ do
 /// ditto
 T* emplace(T, Args...)(void[] memory, auto ref Args args)
 if (!isAggregateType!T && (Args.length <= 1))
-in
-{
-    assert(memory.length >= T.sizeof);
-}
-out (result)
-{
-    assert(memory.ptr is result);
-}
-do
+in (memory.length >= T.sizeof)
+out (result; memory.ptr is result)
 {
     auto result = (() @trusted => cast(T*) memory.ptr)();
     static if (Args.length == 1)
@@ -159,43 +142,57 @@ do
     return result;
 }
 
-/// ditto
-T* emplace(T, Args...)(void[] memory, auto ref Args args)
-if (!isPolymorphicType!T && isAggregateType!T)
-in
+private void initializeOne(T)(ref void[] memory, ref T* result) @trusted
 {
-    assert(memory.length >= T.sizeof);
-}
-out (result)
-{
-    assert(memory.ptr is result);
-}
-do
-{
-    auto result = (() @trusted => cast(T*) memory.ptr)();
     static if (!hasElaborateAssign!T && isAssignable!T)
     {
         *result = T.init;
     }
+    else static if (__VERSION__ >= 2083 // __traits(isZeroInit) available.
+        && __traits(isZeroInit, T))
+    {
+        memory.ptr[0 .. T.sizeof].fill!0;
+    }
     else
     {
-        static const T init = T.init;
-        copy((cast(void*) &init)[0 .. T.sizeof], memory);
+        static immutable T init = T.init;
+        copy((&init)[0 .. 1], memory);
     }
+}
+
+/// ditto
+T* emplace(T, Args...)(void[] memory, auto ref Args args)
+if (!isPolymorphicType!T && isAggregateType!T)
+in (memory.length >= T.sizeof)
+out (result; memory.ptr is result)
+{
+    auto result = (() @trusted => cast(T*) memory.ptr)();
 
     static if (Args.length == 0)
     {
         static assert(is(typeof({ static T t; })),
                       "Default constructor is disabled");
-    }
-    else static if (is(typeof(T(args))))
-    {
-        *result = T(args);
+        initializeOne(memory, result);
     }
     else static if (is(typeof(result.__ctor(args))))
     {
+        initializeOne(memory, result);
         result.__ctor(args);
     }
+    else static if (Args.length == 1 && is(typeof({ T t = args[0]; })))
+    {
+        ((ref arg) @trusted =>
+            copy((cast(void*) &arg)[0 .. T.sizeof], memory))(args[0]);
+        static if (hasElaborateCopyConstructor!T)
+        {
+            result.__postblit();
+        }
+    }
+    else static if (is(typeof({ T t = T(args); })))
+    {
+        auto init = T(args);
+        (() @trusted => moveEmplace(init, *result))();
+    }
     else
     {
         static assert(false,
@@ -243,6 +240,59 @@ do
     static assert(is(typeof(emplace!F((void[]).init))));
 }
 
+// Can emplace structs without a constructor
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(typeof(emplace!WithDtor(null, WithDtor()))));
+    static assert(is(typeof(emplace!WithDtor(null))));
+}
+
+// Doesn't call a destructor on uninitialized elements
+@nogc nothrow pure @system unittest
+{
+    static struct SWithDtor
+    {
+        private bool canBeInvoked = false;
+        ~this() @nogc nothrow pure @safe
+        {
+            assert(this.canBeInvoked);
+        }
+    }
+    void[SWithDtor.sizeof] memory = void;
+    auto actual = emplace!SWithDtor(memory[], SWithDtor(true));
+    assert(actual.canBeInvoked);
+}
+
+// Initializes structs if no arguments are given
+@nogc nothrow pure @safe unittest
+{
+    static struct SEntry
+    {
+        byte content;
+    }
+    ubyte[1] mem = [3];
+
+    assert(emplace!SEntry(cast(void[]) mem[0 .. 1]).content == 0);
+}
+
+// Postblit is called when emplacing a struct
+@nogc nothrow pure @system unittest
+{
+    static struct S
+    {
+        bool called = false;
+        this(this) @nogc nothrow pure @safe
+        {
+            this.called = true;
+        }
+    }
+    S target;
+    S* sp = &target;
+
+    emplace!S(sp[0 .. 1], S());
+    assert(target.called);
+}
+
 /**
  * Thrown if a type conversion fails.
  */
@@ -264,28 +314,178 @@ final class ConvException : Exception
     }
 }
 
-package bool stringToInt(R)(R range, ref ushort n)
+/*
+ * Converts a string $(D_PARAM range) into an integral value of type
+ * $(D_PARAM T) in $(D_PARAM base).
+ *
+ * The convertion stops when $(D_PARAM range) is empty of if the next character
+ * cannot be converted because it is not a digit (with respect to the
+ * $(D_PARAM base)) or if the reading the next character would cause integer
+ * overflow. The function returns the value converted so far then. The front
+ * element of the $(D_PARAM range) points to the first character cannot be
+ * converted or $(D_PARAM range) is empty if the whole string could be
+ * converted.
+ *
+ * Base must be between 2 and 36 inclursive. Default base is 10.
+ *
+ * The function doesn't handle the sign (+ or -) or number prefixes (like 0x).
+ */
+package T readIntegral(T, R)(ref R range, const ubyte base = 10)
+if (isInputRange!R
+ && isSomeChar!(ElementType!R)
+ && isIntegral!T
+ && isUnsigned!T)
+in
 {
-    import tanya.encoding.ascii;
-    import tanya.range.array;
-
-    size_t i = 1;
-    uint lPort;
-
-    for (; !range.empty && range.front.isDigit() && i <= 6; ++i, range.popFront())
+    assert(base >= 2);
+    assert(base <= 36);
+}
+do
+{
+    T boundary = cast(T) (T.max / base);
+    if (range.empty)
     {
-        lPort = lPort * 10 + (range.front - '0');
+        return T.init;
     }
-    if (i != 1 && (range.empty || range.front == '/'))
+
+    T n;
+    int digit;
+    do
     {
-        if (lPort > ushort.max)
+        if (range.front >= 'a')
         {
-            return false;
+            digit = range.front - 'W';
+        }
+        else if (range.front >= 'A' && range.front <= 'Z')
+        {
+            digit = range.front - '7';
+        }
+        else if (range.front >= '0' && range.front <= '9')
+        {
+            digit = range.front - '0';
+        }
+        else
+        {
+            return n;
+        }
+        if (digit >= base)
+        {
+            return n;
+        }
+        n = cast(T) (n * base + digit);
+        range.popFront();
+
+        if (range.empty)
+        {
+            return n;
         }
-        n = cast(ushort) lPort;
-        return true;
     }
-    return false;
+    while (n < boundary);
+
+    if (range.front >= 'a')
+    {
+        digit = range.front - 'W';
+    }
+    else if (range.front >= 'A')
+    {
+        digit = range.front - '7';
+    }
+    else if (range.front >= '0')
+    {
+        digit = range.front - '0';
+    }
+    else
+    {
+        return n;
+    }
+    if (n > cast(T) ((T.max - digit) / base))
+    {
+        return n;
+    }
+    n = cast(T) (n * base + digit);
+    range.popFront();
+
+    return n;
+}
+
+// ':' is not a hex value
+@nogc nothrow pure @safe unittest
+{
+    string colon = ":";
+    auto actual = readIntegral!ubyte(colon, 16);
+    assert(actual == 0);
+    assert(colon.length == 1);
+}
+
+// reads ubyte.max
+@nogc nothrow pure @safe unittest
+{
+    string number = "255";
+    assert(readIntegral!ubyte(number) == 255);
+    assert(number.empty);
+}
+
+// detects integer overflow
+@nogc nothrow pure @safe unittest
+{
+    string number = "500";
+    readIntegral!ubyte(number);
+    assert(number.front == '0');
+    assert(number.length == 1);
+}
+
+// stops on a non-digit
+@nogc nothrow pure @safe unittest
+{
+    string number = "10-";
+    readIntegral!ubyte(number);
+    assert(number.front == '-');
+}
+
+// returns false if the number string is empty
+@nogc nothrow pure @safe unittest
+{
+    string number = "";
+    readIntegral!ubyte(number);
+    assert(number.empty);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    string number = "29";
+    assert(readIntegral!ubyte(number) == 29);
+    assert(number.empty);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    string number = "25467";
+    readIntegral!ubyte(number);
+    assert(number.front == '6');
+}
+
+// Converts lower case hexadecimals
+@nogc nothrow pure @safe unittest
+{
+    string number = "a";
+    assert(readIntegral!ubyte(number, 16) == 10);
+    assert(number.empty);
+}
+
+// Converts upper case hexadecimals
+@nogc nothrow pure @safe unittest
+{
+    string number = "FF";
+    assert(readIntegral!ubyte(number, 16) == 255);
+    assert(number.empty);
+}
+
+// Handles small overflows
+@nogc nothrow pure @safe unittest
+{
+    string number = "256";
+    assert(readIntegral!ubyte(number, 10) == 25);
+    assert(number.front == '6');
 }
 
 /**
@@ -705,30 +905,133 @@ if (is(Unqual!From == bool) && isNumeric!To && !is(Unqual!To == Unqual!From))
 }
 
 /**
- * Converts $(D_PARAM From) to a $(D_PSYMBOL String).
+ * Converts a stringish range to an integral value.
  *
  * Params:
  *  From = Source type.
  *  To   = Target type.
  *  from = Source value.
  *
- * Returns: $(D_PARAM from) converted to $(D_PSYMBOL String).
+ * Returns: $(D_PARAM from) converted to $(D_PARAM To).
+ *
+ * Throws: $(D_PSYMBOL ConvException) if $(D_PARAM from) doesn't contain an
+ *         integral value.
  */
 To to(To, From)(auto ref From from)
-if (is(Unqual!To == String))
+if (isInputRange!From && isSomeChar!(ElementType!From) && isIntegral!To)
 {
-    return format!"{}"(from);
+    if (from.empty)
+    {
+        throw make!ConvException(defaultAllocator, "Input range is empty");
+    }
+
+    static if (isSigned!To)
+    {
+        bool negative;
+    }
+    if (from.front == '-')
+    {
+        static if (isUnsigned!To)
+        {
+            throw make!ConvException(defaultAllocator,
+                                     "Negative integer overflow");
+        }
+        else
+        {
+            negative = true;
+            from.popFront();
+        }
+    }
+
+    if (from.empty)
+    {
+        throw make!ConvException(defaultAllocator, "Input range is empty");
+    }
+
+    ubyte base = 10;
+    if (from.front == '0')
+    {
+        from.popFront();
+        if (from.empty)
+        {
+            return To.init;
+        }
+        else if (from.front == 'x' || from.front == 'X')
+        {
+            base = 16;
+            from.popFront();
+        }
+        else if (from.front == 'b' || from.front == 'B')
+        {
+            base = 2;
+            from.popFront();
+        }
+        else
+        {
+            base = 8;
+        }
+    }
+
+    auto unsigned = readIntegral!(Unsigned!To, From)(from, base);
+    if (!from.empty)
+    {
+        throw make!ConvException(defaultAllocator, "Integer overflow");
+    }
+
+    static if (isSigned!To)
+    {
+        if (negative)
+        {
+            auto predecessor = cast(Unsigned!To) (unsigned - 1);
+            if (predecessor > cast(Unsigned!To) To.max)
+            {
+                throw make!ConvException(defaultAllocator,
+                                         "Negative integer overflow");
+            }
+            return cast(To) (-(cast(Largest!(To, ptrdiff_t)) predecessor) - 1);
+        }
+        else if (unsigned > cast(Unsigned!To) To.max)
+        {
+            throw make!ConvException(defaultAllocator, "Integer overflow");
+        }
+        else
+        {
+            return unsigned;
+        }
+    }
+    else
+    {
+        return unsigned;
+    }
 }
 
 ///
-@nogc nothrow pure @safe unittest
+@nogc pure @safe unittest
 {
-    assert(true.to!String == "true");
-    assert(false.to!String == "false");
-}
+    assert("1234".to!uint() == 1234);
+    assert("1234".to!int() == 1234);
+    assert("1234".to!int() == 1234);
 
-@nogc nothrow pure @safe unittest
-{
-    static assert(is(typeof((const String("true")).to!bool)));
-    static assert(is(typeof(false.to!(const String) == "false")));
+    assert("0".to!int() == 0);
+    assert("-0".to!int() == 0);
+
+    assert("0x10".to!int() == 16);
+    assert("0X10".to!int() == 16);
+    assert("-0x10".to!int() == -16);
+
+    assert("0b10".to!int() == 2);
+    assert("0B10".to!int() == 2);
+    assert("-0b10".to!int() == -2);
+
+    assert("010".to!int() == 8);
+    assert("-010".to!int() == -8);
+
+
+    assert("-128".to!byte == cast(byte) -128);
+
+    assertThrown!ConvException(() => "".to!int);
+    assertThrown!ConvException(() => "-".to!int);
+    assertThrown!ConvException(() => "-5".to!uint);
+    assertThrown!ConvException(() => "-129".to!byte);
+    assertThrown!ConvException(() => "256".to!ubyte);
 }

source/tanya/exception.d

@@ -5,7 +5,7 @@
 /**
  * Common exceptions and errors.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)

source/tanya/functional.d

@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Functions that manipulate other functions and their argument lists.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/functional.d,
+ *                 tanya/functional.d)
+ */
+module tanya.functional;
+
+import tanya.algorithm.mutation;
+import tanya.meta.metafunction;
+
+/**
+ * Forwards its argument list preserving $(D_KEYWORD ref) and $(D_KEYWORD out)
+ * storage classes.
+ *
+ * $(D_PSYMBOL forward) accepts a list of variables or literals. It returns an
+ * argument list of the same length that can be for example passed to a
+ * function accepting the arguments of this type.
+ *
+ * Params:
+ *  args = Argument list.
+ *
+ * Returns: $(D_PARAM args) with their original storage classes.
+ */
+template forward(args...)
+{
+    static if (args.length == 0)
+    {
+        alias forward = AliasSeq!();
+    }
+    else static if (__traits(isRef, args[0]) || __traits(isOut, args[0]))
+    {
+        static if (args.length == 1)
+        {
+            alias forward = args[0];
+        }
+        else
+        {
+            alias forward = AliasSeq!(args[0], forward!(args[1 .. $]));
+        }
+    }
+    else
+    {
+        @property auto forwardOne()
+        {
+            return move(args[0]);
+        }
+        static if (args.length == 1)
+        {
+            alias forward = forwardOne;
+        }
+        else
+        {
+            alias forward = AliasSeq!(forwardOne, forward!(args[1 .. $]));
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(typeof((int i) { int v = forward!i; })));
+    static assert(is(typeof((ref int i) { int v = forward!i; })));
+    static assert(is(typeof({
+        void f(int i, ref int j, out int k)
+        {
+            f(forward!(i, j, k));
+        }
+    })));
+}

source/tanya/hash/lookup.d

@@ -16,6 +16,7 @@ module tanya.hash.lookup;
 
 import tanya.meta.trait;
 import tanya.range.primitive;
+version (unittest) import tanya.test.stub;
 
 private struct FNV
 {
@@ -29,6 +30,11 @@ private struct FNV
         enum ulong offsetBasis = 14695981039346656037UL;
         enum ulong prime = 1099511628211UL;
     }
+    else static if (size_t.sizeof == 16)
+    {
+        enum size_t offsetBasis = (size_t(0x6c62272e07bb0142UL) << 64) + 0x62b821756295c58dUL;
+        enum size_t prime = (size_t(1) << 88) + (1 << 8) + 0x3b;
+    }
     else
     {
         static assert(false, "FNV requires at least 32-bit hash length");
@@ -89,7 +95,10 @@ private struct FNV
  * }
  * ---
  *
- * For scalar types FNV-1a (Fowler-Noll-Vo) hash function is used internally.
+ * For pointers and for scalar types implicitly convertible to `size_t` this
+ * is an identity operation (i.e. the value is cast to `size_t` and returned
+ * unaltered). Integer types wider than `size_t` are XOR folded down to
+ * `size_t`. Other scalar types use the FNV-1a (Fowler-Noll-Vo) hash function.
  * If the type provides a `toHash`-function, only `toHash()` is called and its
  * result is returned.
  *
@@ -110,6 +119,19 @@ size_t hash(T)(auto ref T key)
     {
         return key.toHash();
     }
+    else static if ((isIntegral!T || isSomeChar!T || isBoolean!T)
+            && T.sizeof <= size_t.sizeof)
+    {
+        return cast(size_t) key;
+    }
+    else static if (isIntegral!T && T.sizeof > size_t.sizeof)
+    {
+        return cast(size_t) (key ^ (key >>> (size_t.sizeof * 8)));
+    }
+    else static if (isPointer!T || is(T : typeof(null)))
+    {
+        return (() @trusted => cast(size_t) key)();
+    }
     else
     {
         FNV fnv;
@@ -125,14 +147,6 @@ version (unittest)
                                ~ r10!x ~ r10!x ~ r10!x ~ r10!x ~ r10!x;
     enum string r500(string x) = r100!x ~ r100!x ~ r100!x ~ r100!x ~ r100!x;
 
-    private static struct ToHash
-    {
-        size_t toHash() const @nogc nothrow pure @safe
-        {
-            return 0;
-        }
-    }
-
     private static struct HashRange
     {
         string fo = "fo";
@@ -157,9 +171,9 @@ version (unittest)
     {
         bool empty_;
 
-        @property ToHash front() const @nogc nothrow pure @safe
+        @property Hashable front() const @nogc nothrow pure @safe
         {
-            return ToHash();
+            return Hashable();
         }
 
         void popFront() @nogc nothrow pure @safe
@@ -177,30 +191,29 @@ version (unittest)
 // Tests that work for any hash size
 @nogc nothrow pure @safe unittest
 {
-    assert(hash(null) == FNV.offsetBasis);
-    assert(hash(ToHash()) == 0U);
+    assert(hash(null) == 0);
+    assert(hash(Hashable()) == 0U);
+    assert(hash('a') == 'a');
 }
 
 static if (size_t.sizeof == 4) @nogc nothrow pure @safe unittest
 {
-    assert(hash('a') == 0xe40c292cU);
     assert(hash(HashRange()) == 0x6222e842U);
     assert(hash(ToHashRange()) == 1268118805U);
 }
 static if (size_t.sizeof == 8) @nogc nothrow pure @safe unittest
 {
-    assert(hash('a') == 0xaf63dc4c8601ec8cUL);
     assert(hash(HashRange()) == 0x08985907b541d342UL);
     assert(hash(ToHashRange()) == 12161962213042174405UL);
 }
 
 static if (size_t.sizeof == 4) @nogc nothrow pure @system unittest
 {
-    assert(hash(cast(void*) 0x6e6f6863) == 0xac297727U);
+    assert(hash(cast(void*) 0x6e6f6863) == 0x6e6f6863);
 }
 static if (size_t.sizeof == 8) @nogc nothrow pure @system unittest
 {
-    assert(hash(cast(void*) 0x77206f676e6f6863) == 0xd1edd10b507344d0UL);
+    assert(hash(cast(void*) 0x77206f676e6f6863) == 0x77206f676e6f6863);
 }
 
 /*
@@ -621,3 +634,27 @@ static if (size_t.sizeof == 8) @nogc nothrow pure @safe unittest
     assert(hash(r500!"~") == 0xc1af12bdfe16b5b5UL);
     assert(hash(r500!"\x7f") == 0x39e9f18f2f85e221UL);
 }
+
+/**
+ * Determines whether $(D_PARAM hasher) is hash function for $(D_PARAM T), i.e.
+ * it is callable with a value of type $(D_PARAM T) and returns a
+ * $(D_PSYMBOL size_t) value.
+ *
+ * Params:
+ *  hasher = Hash function candidate.
+ *  T      = Type to test the hash function with.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM hasher) is a hash function for
+ *          $(D_PARAM T), $(D_KEYWORD false) otherwise.
+ */
+template isHashFunction(alias hasher, T)
+{
+    private alias wrapper = (T x) => hasher(x);
+    enum bool isHashFunction = is(typeof(wrapper(T.init)) == size_t);
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static assert(isHashFunction!(hash, int));
+}

source/tanya/math/mp.d

@@ -14,17 +14,15 @@
  */
 module tanya.math.mp;
 
-import std.algorithm.comparison : cmp, equal;
-import std.algorithm.mutation : copy, fill, reverse;
-import std.range;
 import tanya.algorithm.comparison;
+import tanya.algorithm.iteration;
 import tanya.algorithm.mutation;
 import tanya.container.array;
 import tanya.encoding.ascii;
 import tanya.memory;
-static import tanya.memory.op;
 import tanya.meta.trait;
 import tanya.meta.transform;
+import tanya.range;
 
 /**
  * Algebraic sign.
@@ -211,7 +209,7 @@ struct Integer
     this(this) @nogc nothrow pure @safe
     {
         auto tmp = allocator.resize!digit(null, this.size);
-        tanya.memory.op.copy(this.rep[0 .. this.size], tmp);
+        copy(this.rep[0 .. this.size], tmp);
         this.rep = tmp;
     }
 
@@ -344,8 +342,7 @@ struct Integer
     if (is(Unqual!T == Integer))
     {
         this.rep = allocator.resize(this.rep, value.size);
-        tanya.memory.op.copy(value.rep[0 .. value.size],
-                             this.rep[0 .. value.size]);
+        copy(value.rep[0 .. value.size], this.rep[0 .. value.size]);
         this.size = value.size;
         this.sign = value.sign;
 
@@ -631,7 +628,7 @@ struct Integer
         }
         return this.rep[0 .. this.size]
                    .retro
-                   .cmp(that.rep[0 .. that.size].retro);
+                   .compare(that.rep[0 .. that.size].retro);
     }
 
     /**
@@ -932,7 +929,7 @@ struct Integer
             const shift = digitBitCount - bit;
             digit carry;
 
-            foreach (ref d; this.rep[0 .. this.size].retro)
+            foreach_reverse (ref d; this.rep[0 .. this.size])
             {
                 const newCarry = d & mask;
                 d = (d >> bit) | (carry << shift);
@@ -1508,14 +1505,11 @@ struct Integer
             tmp = this;
         }
 
-        do
+        array.length = length;
+        for (size_t i = array.length - 1; tmp != 0; tmp >>= 8, --i)
         {
-            array.insertBack(cast(ubyte) (tmp.rep[0] & 0xff));
-            tmp >>= 8;
+            array[i] = (cast(ubyte) (tmp.rep[0] & 0xff));
         }
-        while (tmp != 0);
-
-        array[].reverse();
 
         return array;
     }

source/tanya/math/package.d

@@ -38,7 +38,7 @@ enum IEEEPrecision : ubyte
 /**
  * Tests the precision of floating-point type $(D_PARAM F).
  *
- * For $(D_KEYWORD float), $(D_PSYMBOL ieeePrecision) always evaluates to
+ * For $(D_KEYWORD float) $(D_PSYMBOL ieeePrecision) always evaluates to
  * $(D_INLINECODE IEEEPrecision.single); for $(D_KEYWORD double) - to
  * $(D_INLINECODE IEEEPrecision.double). It returns different values only
  * for $(D_KEYWORD real), since $(D_KEYWORD real) is a platform-dependent type.
@@ -87,7 +87,7 @@ if (isFloatingPoint!F)
     static assert(ieeePrecision!double == IEEEPrecision.double_);
 }
 
-private union FloatBits(F)
+package(tanya) union FloatBits(F)
 {
     Unqual!F floating;
     static if (ieeePrecision!F == IEEEPrecision.single)
@@ -396,7 +396,7 @@ if (isFloatingPoint!F)
 
 /**
  * Determines whether $(D_PARAM x) is a denormilized number or not.
-
+ *
  * Denormalized number is a number between `0` and `1` that cannot be
  * represented as
  *
@@ -459,7 +459,7 @@ if (isFloatingPoint!F)
 
 /**
  * Determines whether $(D_PARAM x) is a normilized number or not.
-
+ *
  * Normalized number is a number that can be represented as
  *
  * <pre>
@@ -739,101 +739,3 @@ bool isPseudoprime(ulong x) @nogc nothrow pure @safe
     assert(899809363.isPseudoprime);
     assert(982451653.isPseudoprime);
 }
-
-deprecated("Use tanya.algorithm.comparison.min instead")
-T min(T)(T x, T y)
-if (isIntegral!T)
-{
-    return x < y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.min instead")
-T min(T)(T x, T y)
-if (isFloatingPoint!T)
-{
-    if (isNaN(x))
-    {
-        return y;
-    }
-    if (isNaN(y))
-    {
-        return x;
-    }
-    return x < y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.min instead")
-ref T min(T)(ref T x, ref T y)
-if (is(Unqual!T == Integer))
-{
-    return x < y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.min instead")
-T min(T)(T x, T y)
-if (is(T == Integer))
-{
-    return x < y ? move(x) : move(y);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    assert(min(Integer(5), Integer(3)) == 3);
-}
-
-deprecated("Use tanya.algorithm.comparison.max instead")
-T max(T)(T x, T y)
-if (isIntegral!T)
-{
-    return x > y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.max instead")
-T max(T)(T x, T y)
-if (isFloatingPoint!T)
-{
-    if (isNaN(x))
-    {
-        return y;
-    }
-    if (isNaN(y))
-    {
-        return x;
-    }
-    return x > y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.max instead")
-ref T max(T)(ref T x, ref T y)
-if (is(Unqual!T == Integer))
-{
-    return x > y ? x : y;
-}
-
-deprecated("Use tanya.algorithm.comparison.max instead")
-T max(T)(T x, T y)
-if (is(T == Integer))
-{
-    return x > y ? move(x) : move(y);
-}
-
-///
-@nogc nothrow pure @safe unittest
-{
-    assert(max(Integer(5), Integer(3)) == 5);
-}
-
-// min/max accept const and mutable references.
-@nogc nothrow pure @safe unittest
-{
-    {
-        Integer i1 = 5, i2 = 3;
-        assert(min(i1, i2) == 3);
-        assert(max(i1, i2) == 5);
-    }
-    {
-        const Integer i1 = 5, i2 = 3;
-        assert(min(i1, i2) == 3);
-        assert(max(i1, i2) == 5);
-    }
-}

source/tanya/math/random.d

@@ -15,11 +15,8 @@
 module tanya.math.random;
 
 import std.digest.sha;
-import std.typecons;
 import tanya.memory;
-
-/// Block size of entropy accumulator (SHA-512).
-enum blockSize = 64;
+import tanya.typecons;
 
 /// Maximum amount gathered from the entropy sources.
 enum maxGather = 128;
@@ -39,7 +36,7 @@ class EntropyException : Exception
     this(string msg,
          string file = __FILE__,
          size_t line = __LINE__,
-         Throwable next = null) pure @safe nothrow const @nogc
+         Throwable next = null) const @nogc nothrow pure @safe
     {
         super(msg, file, line, next);
     }
@@ -56,17 +53,17 @@ abstract class EntropySource
     /**
      * Returns: Minimum bytes required from the entropy source.
      */
-    @property ubyte threshold() const pure nothrow @safe @nogc;
+    @property ubyte threshold() const @nogc nothrow pure @safe;
 
     /**
      * Returns: Whether this entropy source is strong.
      */
-    @property bool strong() const pure nothrow @safe @nogc;
+    @property bool strong() const @nogc nothrow pure @safe;
 
     /**
      * Returns: Amount of already generated entropy.
      */
-    @property ushort size() const pure nothrow @safe @nogc
+    @property ushort size() const @nogc nothrow pure @safe
     {
         return size_;
     }
@@ -76,7 +73,7 @@ abstract class EntropySource
      *  size = Amount of already generated entropy. Cannot be smaller than the
      *         already set value.
      */
-    @property void size(ushort size) pure nothrow @safe @nogc
+    @property void size(ushort size) @nogc nothrow pure @safe
     {
         size_ = size;
     }
@@ -89,9 +86,13 @@ abstract class EntropySource
      *           to fill the buffer).
      *
      * Returns: Number of bytes that were copied to the $(D_PARAM output)
-     *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
+     *          or nothing on error.
+     *
+     * Postcondition: Returned length is less than or equal to
+     *                $(D_PARAM output) length.
      */
-    Nullable!ubyte poll(out ubyte[maxGather] output) @nogc;
+    Option!ubyte poll(out ubyte[maxGather] output) @nogc
+    out (length; length.isNothing || length.get <= maxGather);
 }
 
 version (CRuntime_Bionic)
@@ -118,7 +119,7 @@ else version (Solaris)
 version (linux)
 {
     import core.stdc.config : c_long;
-    extern (C) c_long syscall(c_long number, ...) nothrow @system @nogc;
+    private extern(C) c_long syscall(c_long number, ...) @nogc nothrow @system;
 
     /**
      * Uses getrandom system call.
@@ -128,7 +129,7 @@ version (linux)
         /**
          * Returns: Minimum bytes required from the entropy source.
          */
-        override @property ubyte threshold() const pure nothrow @safe @nogc
+        override @property ubyte threshold() const @nogc nothrow pure @safe
         {
             return 32;
         }
@@ -136,7 +137,7 @@ version (linux)
         /**
          * Returns: Whether this entropy source is strong.
          */
-        override @property bool strong() const pure nothrow @safe @nogc
+        override @property bool strong() const @nogc nothrow pure @safe
         {
             return true;
         }
@@ -149,19 +150,14 @@ version (linux)
          *           to fill the buffer).
          *
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
-         *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
+         *          or nothing on error.
          */
-        override Nullable!ubyte poll(out ubyte[maxGather] output) nothrow @nogc
-        out (length)
-        {
-            assert(length <= maxGather);
-        }
-        do
+        override Option!ubyte poll(out ubyte[maxGather] output) @nogc nothrow
         {
             // int getrandom(void *buf, size_t buflen, unsigned int flags);
             import mir.linux._asm.unistd : NR_getrandom;
             auto length = syscall(NR_getrandom, output.ptr, output.length, 0);
-            Nullable!ubyte ret;
+            Option!ubyte ret;
 
             if (length >= 0)
             {
@@ -170,19 +166,11 @@ version (linux)
             return ret;
         }
     }
-
-    @nogc @system unittest
-    {
-        auto entropy = defaultAllocator.make!Entropy();
-        ubyte[blockSize] output;
-        output = entropy.random;
-
-        defaultAllocator.dispose(entropy);
-    }
 }
 else version (SecureARC4Random)
 {
-    private extern (C) void arc4random_buf(scope void* buf, size_t nbytes) nothrow @nogc @system;
+    private extern(C) void arc4random_buf(scope void* buf, size_t nbytes)
+    @nogc nothrow @system;
 
     /**
      * Uses arc4random_buf.
@@ -192,7 +180,7 @@ else version (SecureARC4Random)
         /**
          * Returns: Minimum bytes required from the entropy source.
          */
-        override @property ubyte threshold() const pure nothrow @safe @nogc
+        override @property ubyte threshold() const @nogc nothrow pure @safe
         {
             return 32;
         }
@@ -200,7 +188,7 @@ else version (SecureARC4Random)
         /**
          * Returns: Whether this entropy source is strong.
          */
-        override @property bool strong() const pure nothrow @safe @nogc
+        override @property bool strong() const @nogc nothrow pure @safe
         {
             return true;
         }
@@ -213,23 +201,15 @@ else version (SecureARC4Random)
          *           to fill the buffer).
          *
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
-         *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
+         *          or nothing on error.
          */
-        override Nullable!ubyte poll(out ubyte[maxGather] output) nothrow @nogc @safe
+        override Option!ubyte poll(out ubyte[maxGather] output)
+        @nogc nothrow @safe
         {
             (() @trusted => arc4random_buf(output.ptr, output.length))();
-            return Nullable!ubyte(cast(ubyte) (output.length));
+            return Option!ubyte(cast(ubyte) (output.length));
         }
     }
-
-    @nogc @system unittest
-    {
-        auto entropy = defaultAllocator.make!Entropy();
-        ubyte[blockSize] output;
-        output = entropy.random;
-
-        defaultAllocator.dispose(entropy);
-    }
 }
 else version (Windows)
 {
@@ -248,22 +228,31 @@ else version (Windows)
         BOOL CryptReleaseContext(HCRYPTPROV, ULONG_PTR);
     }
 
-    private bool initCryptGenRandom(scope ref HCRYPTPROV hProvider) @nogc nothrow @trusted
+    private bool initCryptGenRandom(scope ref HCRYPTPROV hProvider)
+    @nogc nothrow @trusted
     {
         // https://msdn.microsoft.com/en-us/library/windows/desktop/aa379886(v=vs.85).aspx
         // For performance reasons, we recommend that you set the pszContainer
         // parameter to NULL and the dwFlags parameter to CRYPT_VERIFYCONTEXT
         // in all situations where you do not require a persisted key.
-        // CRYPT_SILENT is intended for use with applications for which the UI cannot be displayed by the CSP.
-        if (!CryptAcquireContextW(&hProvider, null, null, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
+        // CRYPT_SILENT is intended for use with applications for which the UI
+        // cannot be displayed by the CSP.
+        if (!CryptAcquireContextW(&hProvider,
+                                  null,
+                                  null,
+                                  PROV_RSA_FULL,
+                                  CRYPT_VERIFYCONTEXT | CRYPT_SILENT))
         {
-            if (GetLastError() == NTE_BAD_KEYSET)
+            if (GetLastError() != NTE_BAD_KEYSET)
             {
-                // Attempt to create default container
-                if (!CryptAcquireContextA(&hProvider, null, null, PROV_RSA_FULL, CRYPT_NEWKEYSET | CRYPT_SILENT))
-                    return false;
+                return false;
             }
-            else
+            // Attempt to create default container
+            if (!CryptAcquireContextA(&hProvider,
+                                      null,
+                                      null,
+                                      PROV_RSA_FULL,
+                                      CRYPT_NEWKEYSET | CRYPT_SILENT))
             {
                 return false;
             }
@@ -299,7 +288,7 @@ else version (Windows)
         /**
          * Returns: Minimum bytes required from the entropy source.
          */
-        override @property ubyte threshold() const pure nothrow @safe @nogc
+        override @property ubyte threshold() const @nogc nothrow pure @safe
         {
             return 32;
         }
@@ -307,7 +296,7 @@ else version (Windows)
         /**
          * Returns: Whether this entropy source is strong.
          */
-        override @property bool strong() const pure nothrow @safe @nogc
+        override @property bool strong() const @nogc nothrow pure @safe
         {
             return true;
         }
@@ -320,16 +309,14 @@ else version (Windows)
          *           to fill the buffer).
          *
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
-         *          or $(D_PSYMBOL Nullable!ubyte.init) on error.
+         *          or nothing on error.
          */
-        override Nullable!ubyte poll(out ubyte[maxGather] output) @nogc nothrow @safe
-        in
+        override Option!ubyte poll(out ubyte[maxGather] output)
+        @nogc nothrow @safe
         {
-            assert(hProvider > 0, "hProvider not properly initialized.");
-        }
-        do
-        {
-            Nullable!ubyte ret;
+            Option!ubyte ret;
+
+            assert(hProvider > 0, "hProvider not properly initialized");
             if ((() @trusted => CryptGenRandom(hProvider, output.length, cast(PBYTE) output.ptr))())
             {
                 ret = cast(ubyte) (output.length);
@@ -337,185 +324,14 @@ else version (Windows)
             return ret;
         }
     }
-
-    @nogc @system unittest
-    {
-        auto entropy = defaultAllocator.make!Entropy();
-        ubyte[blockSize] output;
-        output = entropy.random;
-
-        defaultAllocator.dispose(entropy);
-    }
 }
 
-/**
- * Pseudorandom number generator.
- * ---
- * auto entropy = defaultAllocator.make!Entropy();
- *
- * ubyte[blockSize] output;
- *
- * output = entropy.random;
- *
- * defaultAllocator.dispose(entropy);
- * ---
- */
-class Entropy
+static if (is(PlatformEntropySource)) @nogc @system unittest
 {
-    /// Entropy sources.
-    protected EntropySource[] sources;
+    import tanya.memory.smartref : unique;
 
-    private ubyte sourceCount_;
+    auto source = defaultAllocator.unique!PlatformEntropySource();
 
-    /// Entropy accumulator.
-    protected SHA!(maxGather * 8, 512) accumulator;
-
-    /**
-     * Params:
-     *  maxSources = Maximum amount of entropy sources can be set.
-     *  allocator  = Allocator to allocate entropy sources available on the
-     *               system.
-     */
-    this(const size_t maxSources = 20,
-         shared Allocator allocator = defaultAllocator) @nogc
-    in
-    {
-        assert(maxSources > 0 && maxSources <= ubyte.max);
-        assert(allocator !is null);
-    }
-    do
-    {
-        allocator.resize(sources, maxSources);
-
-        static if (is(PlatformEntropySource))
-        {
-            this ~= allocator.make!PlatformEntropySource;
-        }
-    }
-
-    /**
-     * Returns: Amount of the registered entropy sources.
-     */
-    @property ubyte sourceCount() const pure nothrow @safe @nogc
-    {
-        return sourceCount_;
-    }
-
-    /**
-     * Add an entropy source.
-     *
-     * Params:
-     *  source = Entropy source.
-     *
-     * Returns: $(D_PSYMBOL this).
-     *
-     * See_Also:
-     *  $(D_PSYMBOL EntropySource)
-     */
-    Entropy opOpAssign(string op)(EntropySource source)
-    pure nothrow @safe @nogc
-    if (op == "~")
-    in
-    {
-        assert(sourceCount_ <= sources.length);
-    }
-    do
-    {
-        sources[sourceCount_++] = source;
-        return this;
-    }
-
-    /**
-     * Returns: Generated random sequence.
-     *
-     * Throws: $(D_PSYMBOL EntropyException) if no strong entropy source was
-     *         registered or it failed.
-     */
-    @property ubyte[blockSize] random() @nogc
-    in
-    {
-        assert(sourceCount_ > 0, "No entropy sources defined.");
-    }
-    do
-    {
-        bool haveStrong;
-        ushort done;
-        ubyte[blockSize] output;
-
-        do
-        {
-            ubyte[maxGather] buffer;
-
-            // Run through our entropy sources
-            for (ubyte i; i < sourceCount; ++i)
-            {
-                auto outputLength = sources[i].poll(buffer);
-
-                if (!outputLength.isNull)
-                {
-                    if (outputLength > 0)
-                    {
-                        update(i, buffer, outputLength);
-                        sources[i].size = cast(ushort) (sources[i].size + outputLength);
-                    }
-                    if (sources[i].size < sources[i].threshold)
-                    {
-                        continue;
-                    }
-                    else if (sources[i].strong)
-                    {
-                        haveStrong = true;
-                    }
-                }
-                done = 257;
-            }
-        }
-        while (++done < 256);
-
-        if (!haveStrong)
-        {
-            throw defaultAllocator.make!EntropyException("No strong entropy source defined.");
-        }
-
-        output = accumulator.finish();
-
-        // Reset accumulator and counters and recycle existing entropy
-        accumulator.start();
-
-        // Perform second SHA-512 on entropy
-        output = sha512Of(output);
-
-        for (ubyte i; i < sourceCount; ++i)
-        {
-            sources[i].size = 0;
-        }
-        return output;
-    }
-
-    /**
-     * Update entropy accumulator.
-     *
-     * Params:
-     *  sourceId = Entropy source index in $(D_PSYMBOL sources).
-     *  data     = Data got from the entropy source.
-     *  length   = Length of the received data.
-     */
-    protected void update(in ubyte sourceId,
-                          ref ubyte[maxGather] data,
-                          ubyte length) pure nothrow @safe @nogc
-    {
-        ubyte[2] header;
-
-        if (length > blockSize)
-        {
-            data[0 .. 64] = sha512Of(data);
-            length = blockSize;
-        }
-
-        header[0] = sourceId;
-        header[1] = length;
-
-        accumulator.put(header);
-        accumulator.put(data[0 .. length]);
-    }
+    assert(source.threshold == 32);
+    assert(source.strong);
 }

source/tanya/memory/op.d

@@ -24,7 +24,7 @@ version (TanyaNative)
     extern private void moveMemory(const void[], void[])
     pure nothrow @system @nogc;
 
-    extern private int cmpMemory(const void[], const void[])
+    extern private bool equalMemory(const void[], const void[])
     pure nothrow @system @nogc;
 }
 else
@@ -40,6 +40,11 @@ version (TanyaNative)
         fillMemory(buffer[1 .. $], 0);
         assert(buffer[0] == 1 && buffer[1] == 0);
     }
+
+    @nogc nothrow pure @safe unittest
+    {
+        assert(equal(null, null));
+    }
 }
 
 private enum alignMask = size_t.sizeof - 1;
@@ -86,7 +91,7 @@ do
     ubyte[9] source = [1, 2, 3, 4, 5, 6, 7, 8, 9];
     ubyte[9] target;
     source.copy(target);
-    assert(cmp(source, target) == 0);
+    assert(equal(source, target));
 }
 
 @nogc nothrow pure @safe unittest
@@ -105,7 +110,7 @@ do
         ubyte[8] source = [1, 2, 3, 4, 5, 6, 7, 8];
         ubyte[8] target;
         source.copy(target);
-        assert(cmp(source, target) == 0);
+        assert(equal(source, target));
     }
 }
 
@@ -207,7 +212,7 @@ do
     ubyte[6] expected = [ 'a', 'a', 'a', 'a', 'b', 'b' ];
 
     copyBackward(mem[0 .. 4], mem[2 .. $]);
-    assert(cmp(expected, mem) == 0);
+    assert(equal(expected, mem));
 }
 
 @nogc nothrow pure @safe unittest
@@ -216,76 +221,7 @@ do
     ubyte[9] r2;
 
     copyBackward(r1, r2);
-    assert(cmp(r1, r2) == 0);
-}
-
-/**
- * Compares two memory areas $(D_PARAM r1) and $(D_PARAM r2).
- *
- * $(D_PSYMBOL cmp) returns a positive integer if
- * $(D_INLINECODE r1.length > r2.length) or the first `n` compared bytes of
- * $(D_PARAM r1) found to be greater than the first `n` bytes of $(D_PARAM r2),
- *
- * $(D_PSYMBOL cmp) returns a negative integer if
- * $(D_INLINECODE r2.length > r1.length) or the first `n` compared bytes of
- * $(D_PARAM r1) found to be less than the first `n` bytes of $(D_PARAM r2),
- *
- * `0` is returned otherwise.
- *
- * Returns: Positive integer if $(D_INLINECODE r1 > r2),
- *          negative integer if $(D_INLINECODE r2 > r1),
- *          `0` if $(D_INLINECODE r1 == r2).
- */
-int cmp(const void[] r1, const void[] r2) @nogc nothrow pure @trusted
-in
-{
-    assert(r1.length == 0 || r1.ptr !is null);
-    assert(r2.length == 0 || r2.ptr !is null);
-}
-do
-{
-    version (TanyaNative)
-    {
-        return cmpMemory(r1, r2);
-    }
-    else
-    {
-        if (r1.length > r2.length)
-        {
-            return 1;
-        }
-        return r1.length < r2.length ? -1 : memcmp(r1.ptr, r2.ptr, r1.length);
-    }
-}
-
-///
-@nogc nothrow pure @safe unittest
-{
-    ubyte[4] r1 = [ 'a', 'b', 'c', 'd' ];
-    ubyte[3] r2 = [ 'c', 'a', 'b' ];
-
-    assert(cmp(r1[0 .. 3], r2[]) < 0);
-    assert(cmp(r2[], r1[0 .. 3]) > 0);
-
-    assert(cmp(r1, r2) > 0);
-    assert(cmp(r2, r1) < 0);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    ubyte[16] r1 = [
-        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
-        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
-    ];
-    ubyte[16] r2 = [
-        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
-        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
-    ];
-
-    assert(cmp(r1, r2) == 0);
-    assert(cmp(r1[1 .. $], r2[1 .. $]) == 0);
-    assert(cmp(r1[0 .. $ - 1], r2[0 .. $ - 1]) == 0);
-    assert(cmp(r1[0 .. 8], r2[0 .. 8]) == 0);
+    assert(equal(r1, r2));
 }
 
 /**
@@ -300,7 +236,7 @@ do
  *          first occurrence of $(D_PARAM needle). If $(D_PARAM needle)
  *          couldn't be found, an empty `inout void[]` is returned.
  */
-inout(void[]) find(return inout void[] haystack, const ubyte needle)
+inout(void[]) find(return inout void[] haystack, ubyte needle)
 @nogc nothrow pure @trusted
 in
 {
@@ -321,19 +257,19 @@ do
         {
             return bytes[0 .. length];
         }
-        bytes++;
-        length--;
+        ++bytes;
+        --length;
     }
 
     // Check if some of the words has the needle
     auto words = cast(inout(size_t)*) bytes;
     while (length >= size_t.sizeof)
     {
-        if (((*words ^ needleWord) - highBits) & (~*words) & mask)
+        if ((((*words ^ needleWord) - highBits) & (~*words) & mask) != 0)
         {
             break;
         }
-        words++;
+        ++words;
         length -= size_t.sizeof;
     }
 
@@ -345,8 +281,8 @@ do
         {
             return bytes[0 .. length];
         }
-        bytes++;
-        length--;
+        ++bytes;
+        --length;
     }
 
     return haystack[$ .. $];
@@ -357,14 +293,145 @@ do
 {
     const ubyte[9] haystack = ['a', 'b', 'c', 'd', 'e', 'f', 'b', 'g', 'h'];
 
-    assert(find(haystack, 'a') == haystack[]);
-    assert(find(haystack, 'b') == haystack[1 .. $]);
-    assert(find(haystack, 'c') == haystack[2 .. $]);
-    assert(find(haystack, 'd') == haystack[3 .. $]);
-    assert(find(haystack, 'e') == haystack[4 .. $]);
-    assert(find(haystack, 'f') == haystack[5 .. $]);
-    assert(find(haystack, 'h') == haystack[8 .. $]);
+    assert(equal(find(haystack, 'a'), haystack[]));
+    assert(equal(find(haystack, 'b'), haystack[1 .. $]));
+    assert(equal(find(haystack, 'c'), haystack[2 .. $]));
+    assert(equal(find(haystack, 'd'), haystack[3 .. $]));
+    assert(equal(find(haystack, 'e'), haystack[4 .. $]));
+    assert(equal(find(haystack, 'f'), haystack[5 .. $]));
+    assert(equal(find(haystack, 'h'), haystack[8 .. $]));
     assert(find(haystack, 'i').length == 0);
 
     assert(find(null, 'a').length == 0);
 }
+
+/**
+ * Looks for `\0` in the $(D_PARAM haystack) and returns the part of the
+ * $(D_PARAM haystack) ahead of it.
+ *
+ * Returns $(D_KEYWORD null) if $(D_PARAM haystack) doesn't contain a null
+ * character.
+ *
+ * Params:
+ *  haystack = Memory block.
+ *
+ * Returns: The subrange that spans all bytes before the null character or
+ *          $(D_KEYWORD null) if the $(D_PARAM haystack) doesn't contain any.
+ */
+inout(char[]) findNullTerminated(return inout char[] haystack)
+@nogc nothrow pure @trusted
+in
+{
+    assert(haystack.length == 0 || haystack.ptr !is null);
+}
+do
+{
+    auto length = haystack.length;
+    enum size_t highBits = filledBytes!(0x01, 0);
+    enum size_t mask = filledBytes!(0x80, 0);
+
+    // Align
+    auto bytes = cast(inout(ubyte)*) haystack;
+    while (length > 0 && ((cast(size_t) bytes) & 3) != 0)
+    {
+        if (*bytes == '\0')
+        {
+            return haystack[0 .. haystack.length - length];
+        }
+        ++bytes;
+        --length;
+    }
+
+    // Check if some of the words contains 0
+    auto words = cast(inout(size_t)*) bytes;
+    while (length >= size_t.sizeof)
+    {
+        if (((*words - highBits) & (~*words) & mask) != 0)
+        {
+            break;
+        }
+        ++words;
+        length -= size_t.sizeof;
+    }
+
+    // Find the exact 0 position in the word
+    bytes = cast(inout(ubyte)*) words;
+    while (length > 0)
+    {
+        if (*bytes == '\0')
+        {
+            return haystack[0 .. haystack.length - length];
+        }
+        ++bytes;
+        --length;
+    }
+
+    return null;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    assert(equal(findNullTerminated("abcdef\0gh"), "abcdef"));
+    assert(equal(findNullTerminated("\0garbage"), ""));
+    assert(equal(findNullTerminated("\0"), ""));
+    assert(equal(findNullTerminated("cstring\0"), "cstring"));
+    assert(findNullTerminated(null) is null);
+    assert(findNullTerminated("abcdef") is null);
+}
+
+/**
+ * Compares two memory areas $(D_PARAM r1) and $(D_PARAM r2) for equality.
+ *
+ * Params:
+ *  r1 = First memory block.
+ *  r2 = Second memory block.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM r1) and $(D_PARAM r2) are equal,
+ *          $(D_KEYWORD false) otherwise.
+ */
+bool equal(const void[] r1, const void[] r2) @nogc nothrow pure @trusted
+in
+{
+    assert(r1.length == 0 || r1.ptr !is null);
+    assert(r2.length == 0 || r2.ptr !is null);
+}
+do
+{
+    version (TanyaNative)
+    {
+        return equalMemory(r1, r2);
+    }
+    else
+    {
+        return r1.length == r2.length
+            && memcmp(r1.ptr, r2.ptr, r1.length) == 0;
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    assert(equal("asdf", "asdf"));
+    assert(!equal("asd", "asdf"));
+    assert(!equal("asdf", "asd"));
+    assert(!equal("asdf", "qwer"));
+}
+
+// Compares unanligned memory
+@nogc nothrow pure @safe unittest
+{
+    ubyte[16] r1 = [
+        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
+        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
+    ];
+    ubyte[16] r2 = [
+        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
+        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
+    ];
+
+    assert(equal(r1, r2));
+    assert(equal(r1[1 .. $], r2[1 .. $]));
+    assert(equal(r1[0 .. $ - 1], r2[0 .. $ - 1]));
+    assert(equal(r1[0 .. 8], r2[0 .. 8]));
+}

source/tanya/memory/package.d

@@ -14,7 +14,7 @@
  */
 module tanya.memory;
 
-import std.algorithm.mutation;
+import tanya.algorithm.mutation;
 import tanya.conv;
 import tanya.exception;
 public import tanya.memory.allocator;
@@ -341,13 +341,7 @@ if (isPolymorphicType!T)
 
 package(tanya) void[] finalize(T)(ref T[] p)
 {
-    static if (hasElaborateDestructor!(typeof(p[0])))
-    {
-        foreach (ref e; p)
-        {
-            destroy(e);
-        }
-    }
+    destroyAll(p);
     return p;
 }
 

source/tanya/memory/smartref.d

@@ -30,6 +30,7 @@ import tanya.exception;
 import tanya.memory;
 import tanya.meta.trait;
 import tanya.range.primitive;
+version (unittest) import tanya.test.stub;
 
 private template Payload(T)
 {
@@ -611,19 +612,11 @@ do
 
 @nogc @system unittest
 {
-    static bool destroyed;
-
-    static struct F
+    size_t destroyed;
     {
-        ~this() @nogc nothrow @safe
-        {
-            destroyed = true;
-        }
+        auto rc = defaultAllocator.refCounted!WithDtor(destroyed);
     }
-    {
-        auto rc = defaultAllocator.refCounted!F();
-    }
-    assert(destroyed);
+    assert(destroyed == 1);
 }
 
 /**

source/tanya/meta/metafunction.d

@@ -116,7 +116,7 @@ if (Args.length > 0 && __traits(isTemplate, pred))
 }
 
 /**
- * Zips one or more $(D_PSYMBOL Tuple)s with $(D_PARAM f).
+ * Zips one or more $(D_PSYMBOL Pack)s with $(D_PARAM f).
  *
  * Given $(D_PARAM f) and tuples t1, t2, ..., tk, where tk[i] denotes the
  * $(I i)-th element of the tuple $(I k)-th tuple, $(D_PSYMBOL ZipWith)
@@ -129,7 +129,7 @@ if (Args.length > 0 && __traits(isTemplate, pred))
  * f(tk[0], tk[1], ... tk[i]),
  * ---
  *
- * $(D_PSYMBOL ZipWith) begins with the first elements from $(D_PARAM Tuples)
+ * $(D_PSYMBOL ZipWith) begins with the first elements from $(D_PARAM Packs)
  * and applies $(D_PARAM f) to them, then it takes the second
  * ones and does the same, and so on.
  *
@@ -140,16 +140,17 @@ if (Args.length > 0 && __traits(isTemplate, pred))
  *
  * Params:
  *  f      = Some template that can be applied to the elements of
- *           $(D_PARAM Tuples).
- *  Tuples = $(D_PSYMBOL Tuple) instances.
+ *           $(D_PARAM Packs).
+ *  Packs  = $(D_PSYMBOL Pack) instances.
  *
  * Returns: A sequence, whose $(I i)-th element contains the $(I i)-th element
- *          from each of the $(D_PARAM Tuples).
+ *          from each of the $(D_PARAM Packs).
  */
-template ZipWith(alias f, Tuples...)
-if (Tuples.length > 0
+template ZipWith(alias f, Packs...)
+if (Packs.length > 0
  && __traits(isTemplate, f)
- && allSatisfy!(ApplyLeft!(isInstanceOf, Tuple), Tuples))
+ && (allSatisfy!(ApplyLeft!(isInstanceOf, Pack), Packs)
+ || allSatisfy!(ApplyLeft!(isInstanceOf, Tuple), Packs)))
 {
     private template GetIth(size_t i, Args...)
     {
@@ -164,43 +165,37 @@ if (Tuples.length > 0
     }
     private template Iterate(size_t i, Args...)
     {
-        alias Tuple = GetIth!(i, Args);
+        alias Pack = GetIth!(i, Args);
 
-        static if (Tuple.length < Tuples.length)
+        static if (Pack.length < Packs.length)
         {
             alias Iterate = AliasSeq!();
         }
         else
         {
-            alias Iterate = AliasSeq!(f!Tuple,
-                                      Iterate!(i + 1, Args));
+            alias Iterate = AliasSeq!(f!Pack, Iterate!(i + 1, Args));
         }
     }
-    alias ZipWith = Iterate!(0, Tuples);
+    alias ZipWith = Iterate!(0, Packs);
 }
 
 ///
 @nogc nothrow pure @safe unittest
 {
-    alias Result1 = ZipWith!(AliasSeq,
-                             Tuple!(1, 2),
-                             Tuple!(5, 6),
-                             Tuple!(9, 10));
+    alias Result1 = ZipWith!(AliasSeq, Pack!(1, 2), Pack!(5, 6), Pack!(9, 10));
     static assert(Result1 == AliasSeq!(1, 5, 9, 2, 6, 10));
 
-    alias Result2 = ZipWith!(AliasSeq,
-                             Tuple!(1, 2, 3),
-                             Tuple!(4, 5));
+    alias Result2 = ZipWith!(AliasSeq, Pack!(1, 2, 3), Pack!(4, 5));
     static assert(Result2 == AliasSeq!(1, 4, 2, 5));
 
-    alias Result3 = ZipWith!(AliasSeq, Tuple!(), Tuple!(4, 5));
+    alias Result3 = ZipWith!(AliasSeq, Pack!(), Pack!(4, 5));
     static assert(Result3.length == 0);
 }
 
 /**
  * Holds a typed sequence of template parameters.
  *
- * Different than $(D_PSYMBOL AliasSeq), $(D_PSYMBOL Tuple) doesn't unpack
+ * Different than $(D_PSYMBOL AliasSeq), $(D_PSYMBOL Pack) doesn't unpack
  * its template parameters automatically. Consider:
  *
  * ---
@@ -215,7 +210,7 @@ if (Tuples.length > 0
  * Using $(D_PSYMBOL AliasSeq) template `A` gets 4 parameters instead of 2,
  * because $(D_PSYMBOL AliasSeq) is just an alias for its template parameters.
  *
- * With $(D_PSYMBOL Tuple) it is possible to pass distinguishable
+ * With $(D_PSYMBOL Pack) it is possible to pass distinguishable
  * sequences of parameters to a template. So:
  *
  * ---
@@ -224,15 +219,15 @@ if (Tuples.length > 0
  *  static assert(Args.length == 2);
  * }
  *
- * alias BInstance = B!(Tuple!(int, uint), Tuple!(float, double));
+ * alias BInstance = B!(Pack!(int, uint), Pack!(float, double));
  * ---
  *
  * Params:
- *  Args = Elements of this $(D_PSYMBOL Tuple).
+ *  Args = Elements of this $(D_PSYMBOL Pack).
  *
  * See_Also: $(D_PSYMBOL AliasSeq).
  */
-struct Tuple(Args...)
+struct Pack(Args...)
 {
     /// Elements in this tuple as $(D_PSYMBOL AliasSeq).
     alias Seq = Args;
@@ -246,9 +241,9 @@ struct Tuple(Args...)
 ///
 @nogc nothrow pure @safe unittest
 {
-    alias A = Tuple!short;
-    alias B = Tuple!(3, 8, 9);
-    alias C = Tuple!(A, B);
+    alias A = Pack!short;
+    alias B = Pack!(3, 8, 9);
+    alias C = Pack!(A, B);
 
     static assert(C.length == 2);
 
@@ -257,7 +252,7 @@ struct Tuple(Args...)
     static assert(B.length == 3);
     static assert(B.Seq == AliasSeq!(3, 8, 9));
 
-    alias D = Tuple!();
+    alias D = Pack!();
     static assert(D.length == 0);
     static assert(is(D.Seq == AliasSeq!()));
 }
@@ -270,7 +265,7 @@ struct Tuple(Args...)
  * for determining if two items are equal.
  *
  * Params:
- *  Args = Elements of this $(D_PSYMBOL Tuple).
+ *  Args = Elements of this $(D_PSYMBOL Set).
  */
 struct Set(Args...)
 {
@@ -1806,3 +1801,62 @@ if (T.length == 2)
     static assert(is(Select!(true, int, float) == int));
     static assert(is(Select!(false, int, float) == float));
 }
+
+/**
+ * Attaces a numeric index to each element from $(D_PARAM Args).
+ *
+ * $(D_PSYMBOL EnumerateFrom) returns a sequence of tuples ($(D_PSYMBOL Pack)s)
+ * consisting of the index of each element and the element itself.
+ *
+ * Params:
+ *  start = Enumeration initial value.
+ *  Args  = Enumerated sequence.
+ *
+ * See_Also: $(D_PSYMBOL Enumerate).
+ */
+template EnumerateFrom(size_t start, Args...)
+{
+    static if (Args.length == 0)
+    {
+        alias EnumerateFrom = AliasSeq!();
+    }
+    else
+    {
+        alias EnumerateFrom = AliasSeq!(Pack!(start, Args[0]), EnumerateFrom!(start + 1, Args[1 .. $]));
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static assert(EnumerateFrom!(0, int, uint, bool).length == 3);
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    alias Expected = AliasSeq!(Pack!(cast(size_t) 0, int),
+                               Pack!(cast(size_t) 1, uint));
+    static assert(is(EnumerateFrom!(0, int, uint) == Expected));
+}
+
+/**
+ * Attaces a numeric index to each element from $(D_PARAM Args).
+ *
+ * $(D_PSYMBOL EnumerateFrom) returns a sequence of tuples ($(D_PSYMBOL Pack)s)
+ * consisting of the index of each element and the element itself.
+ *
+ * Params:
+ *  Args  = Enumerated sequence.
+ *
+ * See_Also: $(D_PSYMBOL EnumerateFrom).
+ */
+alias Enumerate(Args...) = EnumerateFrom!(0, Args);
+
+///
+@nogc nothrow pure @safe unittest
+{
+    alias Expected = AliasSeq!(Pack!(cast(size_t) 0, int),
+                               Pack!(cast(size_t) 1, uint));
+    static assert(is(Enumerate!(int, uint) == Expected));
+}

source/tanya/meta/trait.d

@@ -70,26 +70,6 @@ enum bool isWideString(T) = is(T : const dchar[]) && !isStaticArray!T;
     static assert(!isWideString!(dchar[10]));
 }
 
-deprecated("Use tanya.meta.transform.Smallest instead")
-template Smallest(Args...)
-if (Args.length >= 1)
-{
-    static assert(is(Args[0]), T.stringof ~ " doesn't have .sizeof property");
-
-    static if (Args.length == 1)
-    {
-        alias Smallest = Args[0];
-    }
-    else static if (Smallest!(Args[1 .. $]).sizeof < Args[0].sizeof)
-    {
-        alias Smallest = Smallest!(Args[1 .. $]);
-    }
-    else
-    {
-        alias Smallest = Args[0];
-    }
-}
-
 /**
  * Determines whether $(D_PARAM T) is a complex type.
  *
@@ -178,7 +158,7 @@ enum bool isPolymorphicType(T) = is(T == class) || is(T == interface);
  */
 template hasStaticMember(T, string member)
 {
-    static if (__traits(hasMember, T, member))
+    static if (hasMember!(T, member))
     {
         alias Member = Alias!(__traits(getMember, T, member));
 
@@ -928,26 +908,6 @@ template mostNegative(T)
     static assert(mostNegative!cfloat == -cfloat.max);
 }
 
-deprecated("Use tanya.meta.transform.Largest instead")
-template Largest(Args...)
-if (Args.length >= 1)
-{
-    static assert(is(Args[0]), T.stringof ~ " doesn't have .sizeof property");
-
-    static if (Args.length == 1)
-    {
-        alias Largest = Args[0];
-    }
-    else static if (Largest!(Args[1 .. $]).sizeof > Args[0].sizeof)
-    {
-        alias Largest = Largest!(Args[1 .. $]);
-    }
-    else
-    {
-        alias Largest = Args[0];
-    }
-}
-
 /**
  * Determines whether the type $(D_PARAM T) is copyable.
  *
@@ -1533,6 +1493,8 @@ if (F.length == 1)
 }
 
 /**
+ * Determines whether $(D_PARAM T) defines a symbol $(D_PARAM member).
+ *
  * Params:
  *  T      = Aggregate type.
  *  member = Symbol name.
@@ -1540,7 +1502,6 @@ if (F.length == 1)
  * Returns: $(D_KEYWORD true) if $(D_PARAM T) defines a symbol
  *          $(D_PARAM member), $(D_KEYWORD false) otherwise.
  */
-deprecated("Use __traits(hasMember) instead")
 enum bool hasMember(T, string member) = __traits(hasMember, T, member);
 
 ///
@@ -1642,7 +1603,7 @@ if (is(T == class) || is(T == struct) || is(T == union))
 }
 
 ///
-pure nothrow @safe unittest
+@nogc pure nothrow @safe unittest
 {
     static struct S
     {
@@ -2654,14 +2615,23 @@ if (is(T == enum))
         }
         else
         {
-            alias getEnumMembers = AliasSeq!(__traits(getMember, T, Args[0]), getEnumMembers!(Args[1 .. $]));
+            alias getEnumMembers = AliasSeq!(__traits(getMember, T, Args[0]),
+                                             getEnumMembers!(Args[1 .. $]));
         }
     }
-    alias EnumMembers = getEnumMembers!(__traits(allMembers, T));
+    private alias allMembers = AliasSeq!(__traits(allMembers, T));
+    static if (allMembers.length == 1)
+    {
+        alias EnumMembers = AliasSeq!(__traits(getMember, T, allMembers));
+    }
+    else
+    {
+        alias EnumMembers = getEnumMembers!allMembers;
+    }
 }
 
 ///
-pure nothrow @nogc @safe unittest
+@nogc nothrow pure @safe unittest
 {
     enum E : int
     {
@@ -2669,7 +2639,17 @@ pure nothrow @nogc @safe unittest
         two,
         three,
     }
-    static assert([E.one, E.two, E.three] == [ EnumMembers!E ]);
+    static assert([EnumMembers!E] == [E.one, E.two, E.three]);
+}
+
+// Produces a tuple for an enum with only one member
+@nogc nothrow pure @safe unittest
+{
+    enum E : int
+    {
+        one = 0,
+    }
+    static assert(EnumMembers!E == AliasSeq!0);
 }
 
 /**
@@ -2876,6 +2856,46 @@ template hasUDA(alias symbol, alias attr)
     static assert(!hasUDA!(a, Attr2));
 }
 
+/**
+ * If $(D_PARAM T) is a type, constructs its default value, otherwise
+ * $(D_PSYMBOL evalUDA) aliases itself to $(D_PARAM T).
+ *
+ * This template is useful when working with UDAs with default parameters,
+ * i.e. if an attribute can be given as `@Attr` or `@Attr("param")`,
+ * $(D_PSYMBOL evalUDA) makes `@Attr()` from `@Attr`, but returns
+ * `@Attr("param")` as is.
+ *
+ * $(D_PARAM T) (or its type if it isn't a type already) should have a default
+ * constructor.
+ *
+ * Params:
+ *  T = User Defined Attribute.
+ */
+alias evalUDA(alias T) = T;
+
+/// ditto
+alias evalUDA(T) = Alias!(T());
+
+///
+@nogc nothrow pure @safe unittest
+{
+    static struct Length
+    {
+        size_t length = 8;
+    }
+    @Length @Length(0) int i;
+    alias uda = AliasSeq!(__traits(getAttributes, i));
+
+    alias attr1 = evalUDA!(uda[0]);
+    alias attr2 = evalUDA!(uda[1]);
+
+    static assert(is(typeof(attr1) == Length));
+    static assert(is(typeof(attr2) == Length));
+
+    static assert(attr1.length == 8);
+    static assert(attr2.length == 0);
+}
+
 /**
  * Tests whether $(D_PARAM T) is an inner class, i.e. a class nested inside
  * another class.

source/tanya/net/iface.d

@@ -0,0 +1,228 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Network interfaces.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/net/iface.d,
+ *                 tanya/net/iface.d)
+ */
+module tanya.net.iface;
+
+import tanya.algorithm.comparison;
+import tanya.algorithm.mutation;
+import tanya.container.string;
+import tanya.meta.trait;
+import tanya.meta.transform;
+import tanya.range;
+
+version (TanyaNative)
+{
+    import mir.linux._asm.unistd;
+    import tanya.sys.linux.syscall;
+    import tanya.sys.posix.ioctl;
+    import tanya.sys.posix.net.if_;
+    import tanya.sys.posix.socket;
+}
+else version (Windows)
+{
+    import tanya.sys.windows.ifdef;
+    import tanya.sys.windows.iphlpapi;
+}
+else version (Posix)
+{
+    import core.sys.posix.net.if_;
+}
+
+/**
+ * Converts the name of a network interface to its index.
+ *
+ * If an interface with the name $(D_PARAM name) cannot be found or another
+ * error occurres, returns 0.
+ *
+ * Params:
+ *  name = Interface name.
+ *
+ * Returns: Returns interface index or 0.
+ */
+uint nameToIndex(R)(R name) @trusted
+if (isInputRange!R && is(Unqual!(ElementType!R) == char) && hasLength!R)
+{
+    version (TanyaNative)
+    {
+        if (name.length >= IF_NAMESIZE)
+        {
+            return 0;
+        }
+        ifreq ifreq_ = void;
+
+        copy(name, ifreq_.ifr_name[]);
+        ifreq_.ifr_name[name.length] = '\0';
+
+        auto socket = syscall(AF_INET,
+                              SOCK_DGRAM | SOCK_CLOEXEC,
+                              0,
+                              NR_socket);
+        if (socket <= 0)
+        {
+            return 0;
+        }
+        scope (exit)
+        {
+            syscall(socket, NR_close);
+        }
+        if (syscall(socket,
+                    SIOCGIFINDEX,
+                    cast(ptrdiff_t) &ifreq_,
+                    NR_ioctl) == 0)
+        {
+            return ifreq_.ifr_ifindex;
+        }
+        return 0;
+    }
+    else version (Windows)
+    {
+        if (name.length > IF_MAX_STRING_SIZE)
+        {
+            return 0;
+        }
+        char[IF_MAX_STRING_SIZE + 1] buffer;
+        NET_LUID luid;
+
+        copy(name, buffer[]);
+        buffer[name.length] = '\0';
+
+        if (ConvertInterfaceNameToLuidA(buffer.ptr, &luid) != 0)
+        {
+            return 0;
+        }
+        NET_IFINDEX index;
+        if (ConvertInterfaceLuidToIndex(&luid, &index) == 0)
+        {
+            return index;
+        }
+        return 0;
+    }
+    else version (Posix)
+    {
+        if (name.length >= IF_NAMESIZE)
+        {
+            return 0;
+        }
+        char[IF_NAMESIZE] buffer;
+
+        copy(name, buffer[]);
+        buffer[name.length] = '\0';
+
+        return if_nametoindex(buffer.ptr);
+    }
+}
+
+///
+@nogc nothrow @safe unittest
+{
+    version (linux)
+    {
+        assert(nameToIndex("lo") == 1);
+    }
+    else version (Windows)
+    {
+        assert(nameToIndex("loopback_0") == 1);
+    }
+    else
+    {
+        assert(nameToIndex("lo0") == 1);
+    }
+    assert(nameToIndex("ecafretni") == 0);
+}
+
+/**
+ * Converts the index of a network interface to its name.
+ *
+ * If an interface with the $(D_PARAM index) cannot be found or another
+ * error occurres, returns an empty $(D_PSYMBOL String).
+ *
+ * Params:
+ *  index = Interface index.
+ *
+ * Returns: Returns interface name or an empty $(D_PSYMBOL String).
+ */
+String indexToName(uint index) @nogc nothrow @trusted
+{
+    import tanya.memory.op : findNullTerminated;
+
+    version (TanyaNative)
+    {
+        ifreq ifreq_ = void;
+        ifreq_.ifr_ifindex = index;
+
+        auto socket = syscall(AF_INET,
+                              SOCK_DGRAM | SOCK_CLOEXEC,
+                              0,
+                              NR_socket);
+        if (socket <= 0)
+        {
+            return String();
+        }
+        scope (exit)
+        {
+            syscall(socket, NR_close);
+        }
+        if (syscall(socket,
+                    SIOCGIFNAME,
+                    cast(ptrdiff_t) &ifreq_,
+                    NR_ioctl) == 0)
+        {
+            return String(findNullTerminated(ifreq_.ifr_name));
+        }
+        return String();
+    }
+    else version (Windows)
+    {
+        NET_LUID luid;
+        if (ConvertInterfaceIndexToLuid(index, &luid) != 0)
+        {
+            return String();
+        }
+
+        char[IF_MAX_STRING_SIZE + 1] buffer;
+        if (ConvertInterfaceLuidToNameA(&luid,
+                                        buffer.ptr,
+                                        IF_MAX_STRING_SIZE + 1) != 0)
+        {
+            return String();
+        }
+        return String(findNullTerminated(buffer));
+    }
+    else version (Posix)
+    {
+        char[IF_NAMESIZE] buffer;
+        if (if_indextoname(index, buffer.ptr) is null)
+        {
+            return String();
+        }
+        return String(findNullTerminated(buffer));
+    }
+}
+
+@nogc nothrow @safe unittest
+{
+    version (linux)
+    {
+        assert(equal(indexToName(1)[], "lo"));
+    }
+    else version (Windows)
+    {
+        assert(equal(indexToName(1)[], "loopback_0"));
+    }
+    else
+    {
+        assert(equal(indexToName(1)[], "lo0"));
+    }
+    assert(indexToName(uint.max).empty);
+}

source/tanya/net/inet.d

@@ -16,7 +16,7 @@ module tanya.net.inet;
 
 import tanya.meta.trait;
 import tanya.meta.transform;
-import tanya.range.primitive;
+import tanya.range;
 
 /**
  * Represents an unsigned integer as an $(D_KEYWORD ubyte) range.

source/tanya/net/uri.d

@@ -305,7 +305,14 @@ struct URL
      */
     private bool parsePort(const(char)[] port) @nogc nothrow pure @safe
     {
-        return stringToInt(port[1 .. $], this.port);
+        auto unparsed = port[1 .. $];
+        auto parsed = readIntegral!ushort(unparsed);
+        if (unparsed.length == 0 || unparsed[0] == '/')
+        {
+            this.port = parsed;
+            return true;
+        }
+        return false;
     }
 }
 

source/tanya/network/package.d

@@ -5,7 +5,7 @@
 /**
  * Network programming.
  *
- * Copyright: Eugene Wissner 2016-2017.
+ * Copyright: Eugene Wissner 2016-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)

source/tanya/network/socket.d

@@ -5,7 +5,43 @@
 /**
  * Low-level socket programming.
  *
- * Copyright: Eugene Wissner 2016-2017.
+ * Current API supports only server-side TCP communication.
+ *
+ * Here is an example of a cross-platform blocking server:
+ *
+ * ---
+ * import std.stdio;
+ * import tanya.memory;
+ * import tanya.network;
+ *
+ * void main()
+ * {
+ *     auto socket = defaultAllocator.make!StreamSocket(AddressFamily.inet);
+ *     auto address = defaultAllocator.make!InternetAddress("127.0.0.1",
+ *                                                          cast(ushort) 8192);
+ *
+ *     socket.setOption(SocketOptionLevel.SOCKET, SocketOption.REUSEADDR, true);
+ *     socket.blocking = true;
+ *     socket.bind(address);
+ *     socket.listen(5);
+ *
+ *     auto client = socket.accept();
+ *     client.send(cast(const(ubyte)[]) "Test\n");
+ *
+ *     ubyte[100] buf;
+ *     auto response = client.receive(buf[]);
+ *
+ *     writeln(cast(const(char)[]) buf[0 .. response]);
+ *
+ *     defaultAllocator.dispose(client);
+ *     defaultAllocator.dispose(socket);
+ * }
+ * ---
+ *
+ * For an example of an asynchronous server refer to the documentation of the
+ * $(D_PSYMBOL tanya.async.loop) module.
+ *
+ * Copyright: Eugene Wissner 2016-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -17,10 +53,10 @@ module tanya.network.socket;
 import core.stdc.errno;
 import core.time;
 public import std.socket : SocketOption, SocketOptionLevel;
-import std.traits;
-import std.typecons;
 import tanya.algorithm.comparison;
+import tanya.bitmanip;
 import tanya.memory;
+import tanya.meta.trait;
 import tanya.os.error;
 
 /// Value returned by socket operations on error.
@@ -76,17 +112,10 @@ else version (Windows)
                                        socket,
                                        socklen_t,
                                        SOL_SOCKET,
+                                       WSAEWOULDBLOCK,
                                        WSAGetLastError;
     import tanya.async.iocp;
     import tanya.sys.windows.def;
-    import tanya.sys.windows.error : ECONNABORTED = WSAECONNABORTED,
-                                     ENOBUFS = WSAENOBUFS,
-                                     EOPNOTSUPP = WSAEOPNOTSUPP,
-                                     EPROTONOSUPPORT = WSAEPROTONOSUPPORT,
-                                     EPROTOTYPE = WSAEPROTOTYPE,
-                                     ESOCKTNOSUPPORT = WSAESOCKTNOSUPPORT,
-                                     ETIMEDOUT = WSAETIMEDOUT,
-                                     EWOULDBLOCK = WSAEWOULDBLOCK;
     public import tanya.sys.windows.winbase;
     public import tanya.sys.windows.winsock2;
 
@@ -469,7 +498,7 @@ struct Linger
      *
      * See_Also: $(D_PSYMBOL time).
      */
-    @property enabled(const bool value) pure nothrow @safe @nogc
+    @property void enabled(const bool value) pure nothrow @safe @nogc
     {
         this.l_onoff = value;
     }
@@ -580,37 +609,6 @@ enum AddressFamily : int
     inet6     = 10,    /// IP version 6.
 }
 
-deprecated("Use tanya.os.error.ErrorCode.ErrorNo instead")
-enum SocketError : int
-{
-    /// Unknown error.
-    unknown                = 0,
-    /// Firewall rules forbid connection.
-    accessDenied           = EPERM,
-    /// A socket operation was attempted on a non-socket.
-    notSocket              = EBADF,
-    /// The network is not available.
-    networkDown            = ECONNABORTED,
-    /// An invalid pointer address was detected by the underlying socket provider.
-    fault                  = EFAULT,
-    /// An invalid argument was supplied to a $(D_PSYMBOL Socket) member.
-    invalidArgument        = EINVAL,
-    /// The limit on the number of open sockets has been reached.
-    tooManyOpenSockets     = ENFILE,
-    /// No free buffer space is available for a Socket operation.
-    noBufferSpaceAvailable = ENOBUFS,
-    /// The address family is not supported by the protocol family.
-    operationNotSupported  = EOPNOTSUPP,
-    /// The protocol is not implemented or has not been configured.
-    protocolNotSupported   = EPROTONOSUPPORT,
-    /// Protocol error.
-    protocolError          = EPROTOTYPE,
-    /// The connection attempt timed out, or the connected host has failed to respond.
-    timedOut               = ETIMEDOUT,
-    /// The support for the specified socket type does not exist in this address family.
-    socketNotSupported     = ESOCKTNOSUPPORT,
-}
-
 /**
  * $(D_PSYMBOL SocketException) should be thrown only if one of the socket functions
  * $(D_PSYMBOL socketError) and sets $(D_PSYMBOL errno), because
@@ -1440,7 +1438,7 @@ bool wouldHaveBlocked() nothrow @trusted @nogc
     else version (Windows)
     {
         return WSAGetLastError() == ERROR_IO_PENDING
-            || WSAGetLastError() == EWOULDBLOCK
+            || WSAGetLastError() == WSAEWOULDBLOCK
             || WSAGetLastError() == ERROR_IO_INCOMPLETE;
     }
 }

source/tanya/os/package.d

@@ -6,7 +6,7 @@
  * This package provides platform-independent interfaces to operating system
  * functionality.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)

source/tanya/range/adapter.d

@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Range adapters.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/range/adapter.d,
+ *                 tanya/range/adapter.d)
+ */
+module tanya.range.adapter;

source/tanya/range/array.d

@@ -54,7 +54,7 @@ module tanya.range.array;
  *
  * Precondition: $(D_INLINECODE array.length > 0).
  */
-@property ref T front(T)(T[] array)
+@property ref inout(T) front(T)(return scope inout(T)[] array)
 in
 {
     assert(array.length > 0);
@@ -94,7 +94,7 @@ do
  *
  * Precondition: $(D_INLINECODE array.length > 0).
  */
-@property ref T back(T)(T[] array)
+@property ref inout(T) back(T)(return scope inout(T)[] array)
 in
 {
     assert(array.length > 0);
@@ -133,7 +133,7 @@ do
  *
  * Precondition: $(D_INLINECODE array.length > 0).
  */
-void popFront(T)(ref T[] array)
+void popFront(T)(scope ref inout(T)[] array)
 in
 {
     assert(array.length > 0);
@@ -144,7 +144,7 @@ do
 }
 
 /// ditto
-void popBack(T)(ref T[] array)
+void popBack(T)(scope ref inout(T)[] array)
 in
 {
     assert(array.length > 0);
@@ -178,7 +178,7 @@ do
  * Returns: $(D_KEYWORD true) if $(D_PARAM array) has no elements,
  *          $(D_KEYWORD false) otherwise.
  */
-@property bool empty(T)(const T[] array)
+@property bool empty(T)(scope const T[] array)
 {
     return array.length == 0;
 }
@@ -203,7 +203,7 @@ do
  *
  * Returns: A copy of the slice $(D_PARAM array).
  */
-@property T[] save(T)(T[] array)
+@property inout(T)[] save(T)(return scope inout(T)[] array)
 {
     return array;
 }

source/tanya/range/package.d

@@ -15,5 +15,6 @@
  */
 module tanya.range;
 
+public import tanya.range.adapter;
 public import tanya.range.array;
 public import tanya.range.primitive;

source/tanya/range/primitive.d

@@ -14,12 +14,25 @@
  */
 module tanya.range.primitive;
 
+import tanya.algorithm.comparison;
 import tanya.algorithm.mutation;
-import tanya.math;
 import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.range.array;
 
+version (unittest)
+{
+    import tanya.test.stub;
+
+    private struct AssertPostblit
+    {
+        this(this) @nogc nothrow pure @safe
+        {
+            assert(false);
+        }
+    }
+}
+
 /**
  * Returns the element type of the range $(D_PARAM R).
  *
@@ -73,10 +86,7 @@ template ElementType(R)
  *
  * See_Also: $(D_PSYMBOL isInfinite).
  */
-template hasLength(R)
-{
-    enum bool hasLength = is(ReturnType!((R r) => r.length) == size_t);
-}
+enum bool hasLength(R) = is(ReturnType!((R r) => r.length) == size_t);
 
 ///
 @nogc nothrow pure @safe unittest
@@ -294,34 +304,6 @@ template hasSlicing(R)
     static assert(hasSlicing!D);
 }
 
-version (unittest)
-{
-    mixin template InputRangeStub()
-    {
-        @property int front() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
-        @property bool empty() const @nogc nothrow pure @safe
-        {
-            return false;
-        }
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-    }
-    mixin template BidirectionalRangeStub()
-    {
-        @property int back() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
-        void popBack() @nogc nothrow pure @safe
-        {
-        }
-    }
-}
-
 private template isDynamicArrayRange(R)
 {
     static if (is(R E : E[]))
@@ -334,6 +316,26 @@ private template isDynamicArrayRange(R)
     }
 }
 
+private struct Primitive(Candidate, string primitive)
+{
+    auto ref returnType(Candidate candidate)
+    {
+        mixin("return candidate." ~ primitive ~ ";");
+    }
+
+    alias ReturnType = .ReturnType!returnType;
+    static assert(!is(ReturnType == void));
+
+    enum uint attributes = functionAttributes!returnType
+                         & FunctionAttribute.ref_;
+
+    bool opEquals(That)(That) const
+    {
+        return is(ReturnType == That.ReturnType)
+            && attributes == That.attributes;
+    }
+}
+
 /**
  * Determines whether $(D_PARAM R) is an input range.
  *
@@ -353,11 +355,11 @@ private template isDynamicArrayRange(R)
  */
 template isInputRange(R)
 {
-    static if (is(ReturnType!((R r) => r.front()) U)
+    static if (is(Primitive!(R, "front()") U)
             && is(ReturnType!((R r) => r.empty) == bool)
             && is(typeof(R.popFront())))
     {
-        enum bool isInputRange = !is(U == void);
+        enum bool isInputRange = true;
     }
     else
     {
@@ -373,10 +375,12 @@ template isInputRange(R)
         void popFront() @nogc nothrow pure @safe
         {
         }
+
         int front() @nogc nothrow pure @safe
         {
             return 0;
         }
+
         bool empty() const @nogc nothrow pure @safe
         {
             return true;
@@ -391,13 +395,8 @@ template isInputRange(R)
 {
     static struct Range1(T)
     {
-        void popFront()
-        {
-        }
-        int front()
-        {
-            return 0;
-        }
+        mixin InputRangeStub;
+
         T empty() const
         {
             return true;
@@ -408,50 +407,56 @@ template isInputRange(R)
 
     static struct Range2
     {
+        mixin InputRangeStub;
+
         int popFront() @nogc nothrow pure @safe
         {
             return 100;
         }
-        int front() @nogc nothrow pure @safe
-        {
-            return 100;
-        }
-        bool empty() const @nogc nothrow pure @safe
-        {
-            return true;
-        }
     }
     static assert(isInputRange!Range2);
 
     static struct Range3
     {
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
+        mixin InputRangeStub;
+
         void front() @nogc nothrow pure @safe
         {
         }
-        bool empty() const @nogc nothrow pure @safe
-        {
-            return true;
-        }
     }
     static assert(!isInputRange!Range3);
 
     static struct Range4
     {
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-        int front() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
+        mixin InputRangeStub;
+
         enum bool empty = false;
     }
     static assert(isInputRange!Range4);
 }
 
+// Ranges with non-copyable elements can be input ranges
+@nogc nothrow pure @safe unittest
+{
+    @WithLvalueElements
+    static struct R
+    {
+        mixin InputRangeStub!NonCopyable;
+    }
+    static assert(isInputRange!R);
+}
+
+// Ranges with const non-copyable elements can be input ranges
+@nogc nothrow pure @safe unittest
+{
+    @WithLvalueElements
+    static struct R
+    {
+        mixin InputRangeStub!(const(NonCopyable));
+    }
+    static assert(isInputRange!R);
+}
+
 /**
  * Determines whether $(D_PARAM R) is a forward range.
  *
@@ -489,14 +494,17 @@ template isForwardRange(R)
         void popFront() @nogc nothrow pure @safe
         {
         }
+
         int front() @nogc nothrow pure @safe
         {
             return 0;
         }
+
         bool empty() const @nogc nothrow pure @safe
         {
             return true;
         }
+
         typeof(this) save() @nogc nothrow pure @safe
         {
             return this;
@@ -515,6 +523,7 @@ template isForwardRange(R)
     static struct Range2
     {
         mixin InputRangeStub;
+
         Range1 save() @nogc nothrow pure @safe
         {
             return Range1();
@@ -525,6 +534,7 @@ template isForwardRange(R)
     static struct Range3
     {
         mixin InputRangeStub;
+
         const(typeof(this)) save() const @nogc nothrow pure @safe
         {
             return this;
@@ -553,11 +563,11 @@ template isForwardRange(R)
  */
 template isBidirectionalRange(R)
 {
-    static if (is(ReturnType!((R r) => r.back()) U)
+    static if (is(Primitive!(R, "back()") U)
             && is(typeof(R.popBack())))
     {
         enum bool isBidirectionalRange = isForwardRange!R
-                                      && is(U == ReturnType!((R r) => r.front()));
+                                      && (U() == Primitive!(R, "front()")());
     }
     else
     {
@@ -573,21 +583,26 @@ template isBidirectionalRange(R)
         void popFront() @nogc nothrow pure @safe
         {
         }
+
         void popBack() @nogc nothrow pure @safe
         {
         }
+
         @property int front() @nogc nothrow pure @safe
         {
             return 0;
         }
+
         @property int back() @nogc nothrow pure @safe
         {
             return 0;
         }
+
         bool empty() const @nogc nothrow pure @safe
         {
             return true;
         }
+
         Range save() @nogc nothrow pure @safe
         {
             return this;
@@ -602,33 +617,33 @@ template isBidirectionalRange(R)
 {
     static struct Range(T, U)
     {
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-        void popBack() @nogc nothrow pure @safe
-        {
-        }
+        mixin BidirectionalRangeStub;
+
         @property T front() @nogc nothrow pure @safe
         {
             return T.init;
         }
+
         @property U back() @nogc nothrow pure @safe
         {
             return U.init;
         }
-        bool empty() const @nogc nothrow pure @safe
-        {
-            return true;
-        }
-        Range save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
     }
     static assert(!isBidirectionalRange!(Range!(int, uint)));
     static assert(!isBidirectionalRange!(Range!(int, const int)));
 }
 
+// Ranges with non-copyable elements can be bidirectional ranges
+@nogc nothrow pure @safe unittest
+{
+    @WithLvalueElements
+    static struct R
+    {
+        mixin BidirectionalRangeStub!NonCopyable;
+    }
+    static assert(isBidirectionalRange!R);
+}
+
 /**
  * Determines whether $(D_PARAM R) is a random-access range.
  *
@@ -654,11 +669,11 @@ template isBidirectionalRange(R)
  */
 template isRandomAccessRange(R)
 {
-    static if (is(ReturnType!((R r) => r.opIndex(size_t.init)) U))
+    static if (is(Primitive!(R, "opIndex(size_t.init)") U))
     {
         enum bool isRandomAccessRange = isInputRange!R
                                      && (hasLength!R || isInfinite!R)
-                                     && is(U == ReturnType!((R r) => r.front()));
+                                     && (U() == Primitive!(R, "front()")());
     }
     else
     {
@@ -674,29 +689,22 @@ template isRandomAccessRange(R)
         void popFront() @nogc nothrow pure @safe
         {
         }
-        void popBack() @nogc nothrow pure @safe
-        {
-        }
+
         @property int front() @nogc nothrow pure @safe
         {
             return 0;
         }
-        @property int back() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
+
         bool empty() const @nogc nothrow pure @safe
         {
             return true;
         }
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
-        int opIndex(const size_t pos) @nogc nothrow pure @safe
+
+        int opIndex(size_t) @nogc nothrow pure @safe
         {
             return 0;
         }
+
         size_t length() const @nogc nothrow pure @safe
         {
             return 0;
@@ -711,15 +719,14 @@ template isRandomAccessRange(R)
         void popFront() @nogc nothrow pure @safe
         {
         }
+
         @property int front() @nogc nothrow pure @safe
         {
             return 0;
         }
+
         enum bool empty = false;
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
+
         int opIndex(const size_t pos) @nogc nothrow pure @safe
         {
             return 0;
@@ -732,76 +739,43 @@ template isRandomAccessRange(R)
 {
     static struct Range1
     {
-        mixin InputRangeStub;
         mixin BidirectionalRangeStub;
-
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
-        int opIndex(const size_t pos) @nogc nothrow pure @safe
-        {
-            return 0;
-        }
+        mixin RandomAccessRangeStub;
     }
     static assert(!isRandomAccessRange!Range1);
 
+    @Length
     static struct Range2(Args...)
     {
-        mixin InputRangeStub;
         mixin BidirectionalRangeStub;
 
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
         int opIndex(Args) @nogc nothrow pure @safe
         {
             return 0;
         }
-        size_t length() const @nogc nothrow pure @safe
-        {
-            return 0;
-        }
     }
     static assert(isRandomAccessRange!(Range2!size_t));
     static assert(!isRandomAccessRange!(Range2!()));
     static assert(!isRandomAccessRange!(Range2!(size_t, size_t)));
 
+    @Length
     static struct Range3
     {
-        mixin InputRangeStub;
         mixin BidirectionalRangeStub;
 
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
         int opIndex(const size_t pos1, const size_t pos2 = 0)
         @nogc nothrow pure @safe
         {
             return 0;
         }
-        size_t length() const @nogc nothrow pure @safe
-        {
-            return 0;
-        }
     }
     static assert(isRandomAccessRange!Range3);
 
     static struct Range4
     {
-        mixin InputRangeStub;
         mixin BidirectionalRangeStub;
+        mixin RandomAccessRangeStub;
 
-        typeof(this) save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
-        int opIndex(const size_t pos1) @nogc nothrow pure @safe
-        {
-            return 0;
-        }
         size_t opDollar() const @nogc nothrow pure @safe
         {
             return 0;
@@ -810,20 +784,42 @@ template isRandomAccessRange(R)
     static assert(!isRandomAccessRange!Range4);
 }
 
+// Ranges with non-copyable elements can be random-access ranges
+@nogc nothrow pure @safe unittest
+{
+    @WithLvalueElements @Infinite
+    static struct R
+    {
+        mixin RandomAccessRangeStub!NonCopyable;
+    }
+    static assert(isRandomAccessRange!R);
+}
+
 /**
  * Puts $(D_PARAM e) into the $(D_PARAM range).
  *
- * $(D_PSYMBOL R) should be an output range for $(D_PARAM E).
- *
- * $(D_PARAM range) is advanced after putting an element into it if all of the
- * following conditions are met:
+ * $(D_PSYMBOL R) should be an output range for $(D_PARAM E). It doesn't mean
+ * that everything $(D_PARAM range) is an output range for can be put into it,
+ * but only if one of the following conditions is met:
  *
  * $(OL
- *  $(LI $(D_PSYMBOL R) is an input range)
- *  $(LI $(D_PSYMBOL R) doesn't define a `put`-method)
+ *  $(LI $(D_PARAM R) defines a `put`-method for $(D_PARAM E))
  *  $(LI $(D_PARAM e) can be assigned to $(D_INLINECODE range.front))
+ *  $(LI $(D_PARAM e) can be put into $(D_PARAM range) using
+ *       $(D_INLINECODE range(e))
+ *  )
  * )
  *
+ * The method to put $(D_PARAM e) into $(D_PARAM range) is chosen based on the
+ * order specified above.
+ *
+ * If $(D_PARAM E) is an input range and $(D_PARAM R) is an output range for
+ * its elements as well, use $(D_PSYMBOL tanya.algorithm.mutation.copy)
+ * instead.
+ *
+ * $(D_PARAM range) is advanced after putting an element into it if it is an
+ * input range that doesn't define a `put`-method.
+ *
  * Params:
  *  R     = Target range type.
  *  E     = Source element type.
@@ -849,13 +845,6 @@ void put(R, E)(ref R range, auto ref E e)
     {
         range(e);
     }
-    else static if (isInputRange!E)
-    {
-        for (; !e.empty; e.popFront())
-        {
-            put(range, e.front);
-        }
-    }
     else
     {
         static assert(false, R.stringof ~ " is not an output range for "
@@ -907,17 +896,6 @@ void put(R, E)(ref R range, auto ref E e)
     assert(oc.e == 2);
 }
 
-///
-@nogc nothrow pure @safe unittest
-{
-    int[2] actual;
-    int[2] expected = [2, 3];
-    auto slice = actual[];
-
-    put(slice, expected[]);
-    assert(actual == expected);
-}
-
 /**
  * Determines whether $(D_PARAM R) is an output range for the elemens of type
  * $(D_PARAM E).
@@ -963,7 +941,22 @@ void put(R, E)(ref R range, auto ref E e)
  * Returns: $(D_KEYWORD true) if $(D_PARAM R) is an output range for the
  *          elements of the type $(D_PARAM E), $(D_KEYWORD false) otherwise.
  */
-enum bool isOutputRange(R, E) = is(typeof((ref R r, ref E e) => put(r, e)));
+template isOutputRange(R, E)
+{
+    static if (is(typeof((R r, E e) => put(r, e))))
+    {
+        enum bool isOutputRange = true;
+    }
+    else static if (isInputRange!E)
+    {
+        alias ET = ElementType!E;
+        enum bool isOutputRange = is(typeof((R r, ET e) => put(r, e)));
+    }
+    else
+    {
+        enum bool isOutputRange = false;
+    }
+}
 
 ///
 @nogc nothrow pure @safe unittest
@@ -1089,28 +1082,20 @@ template isInfinite(R)
 
 @nogc nothrow pure @safe unittest
 {
+    @Infinite
     static struct StaticConstRange
     {
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-        @property int front() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
+        mixin InputRangeStub;
+
         static bool empty = false;
     }
     static assert(!isInfinite!StaticConstRange);
 
+    @Infinite
     static struct TrueRange
     {
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-        @property int front() @nogc nothrow pure @safe
-        {
-            return 0;
-        }
+        mixin InputRangeStub;
+
         static const bool empty = true;
     }
     static assert(!isInfinite!TrueRange);
@@ -1340,15 +1325,12 @@ if (isBidirectionalRange!R)
 
 @nogc nothrow pure @safe unittest
 {
+    @Infinite
     static struct InfiniteRange
     {
+        mixin ForwardRangeStub;
         private int i;
 
-        InfiniteRange save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
-
         void popFront() @nogc nothrow pure @safe
         {
             ++this.i;
@@ -1368,8 +1350,6 @@ if (isBidirectionalRange!R)
         {
             return this.i;
         }
-
-        enum bool empty = false;
     }
     {
         InfiniteRange range;
@@ -1489,44 +1469,19 @@ if (isInputRange!R)
 
 @nogc nothrow pure @safe unittest
 {
-    static struct Element
-    {
-        this(this) @nogc nothrow pure @safe
-        {
-            assert(false);
-        }
-    }
-
     // Returns its elements by reference.
+    @Infinite @WithLvalueElements
     static struct R1
     {
-        Element element;
-        enum bool empty = false;
-
-        ref Element front() @nogc nothrow pure @safe
-        {
-            return element;
-        }
-
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
+        mixin InputRangeStub!AssertPostblit;
     }
     static assert(is(typeof(moveFront(R1()))));
 
     // Returns elements with a postblit constructor by value. moveFront fails.
+    @Infinite
     static struct R2
     {
-        enum bool empty = false;
-
-        Element front() @nogc nothrow pure @safe
-        {
-            return Element();
-        }
-
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
+        mixin InputRangeStub!AssertPostblit;
     }
     static assert(!is(typeof(moveFront(R2()))));
 }
@@ -1574,58 +1529,19 @@ if (isBidirectionalRange!R)
 
 @nogc nothrow pure @safe unittest
 {
-    static struct Element
-    {
-        this(this) @nogc nothrow pure @safe
-        {
-            assert(false);
-        }
-    }
-
     // Returns its elements by reference.
+    @Infinite @WithLvalueElements
     static struct R1
     {
-        Element element;
-        enum bool empty = false;
-
-        ref Element back() @nogc nothrow pure @safe
-        {
-            return element;
-        }
-        alias front = back;
-
-        void popBack() @nogc nothrow pure @safe
-        {
-        }
-        alias popFront = popBack;
-
-        R1 save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
+        mixin BidirectionalRangeStub!AssertPostblit;
     }
     static assert(is(typeof(moveBack(R1()))));
 
     // Returns elements with a postblit constructor by value. moveBack fails.
+    @Infinite
     static struct R2
     {
-        enum bool empty = false;
-
-        Element back() @nogc nothrow pure @safe
-        {
-            return Element();
-        }
-        alias front = back;
-
-        void popBack() @nogc nothrow pure @safe
-        {
-        }
-        alias popFront = popBack;
-
-        R2 save() @nogc nothrow pure @safe
-        {
-            return this;
-        }
+        mixin BidirectionalRangeStub!AssertPostblit;
     }
     static assert(!is(typeof(moveBack(R2()))));
 }
@@ -1672,54 +1588,19 @@ if (isRandomAccessRange!R)
 
 @nogc nothrow pure @safe unittest
 {
-    static struct Element
-    {
-        this(this) @nogc nothrow pure @safe
-        {
-            assert(false);
-        }
-    }
-
     // Returns its elements by reference.
+    @Infinite @WithLvalueElements
     static struct R1
     {
-        Element element;
-        enum bool empty = false;
-
-        ref Element front() @nogc nothrow pure @safe
-        {
-            return element;
-        }
-
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-
-        ref Element opIndex(size_t)
-        {
-            return element;
-        }
+        mixin RandomAccessRangeStub!AssertPostblit;
     }
     static assert(is(typeof(moveAt(R1(), 0))));
 
     // Returns elements with a postblit constructor by value. moveAt fails.
+    @Infinite
     static struct R2
     {
-        enum bool empty = false;
-
-        Element front() @nogc nothrow pure @safe
-        {
-            return Element();
-        }
-
-        void popFront() @nogc nothrow pure @safe
-        {
-        }
-
-        Element opIndex() @nogc nothrow pure @safe
-        {
-            return Element();
-        }
+        mixin RandomAccessRangeStub!AssertPostblit;
     }
     static assert(!is(typeof(moveAt(R2(), 0))));
 }
@@ -1820,7 +1701,7 @@ template hasMobileElements(R)
  */
 template hasLvalueElements(R)
 {
-    private alias refDg = (ref ElementType!R e) => e;
+    private alias refDg = (ref ElementType!R e) => &e;
 
     static if (isRandomAccessRange!R)
     {
@@ -1878,6 +1759,12 @@ template hasLvalueElements(R)
     static assert(hasLvalueElements!R2);
 }
 
+// Works with non-copyable elements
+@nogc nothrow pure @safe unittest
+{
+    static assert(hasLvalueElements!(NonCopyable[]));
+}
+
 /**
  * Determines whether the elements of $(D_PARAM R) are assignable.
  *
@@ -2033,3 +1920,41 @@ template hasSwappableElements(R)
     }
     static assert(!hasSwappableElements!R2);
 }
+
+/**
+ * Determines whether `r1.front` and `r2.front` point to the same element.
+ *
+ * Params:
+ *  r1 = First range.
+ *  r2 = Second range.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM r1) and $(D_PARAM r2) have the same
+ *          head, $(D_KEYWORD false) otherwise.
+ */
+bool sameHead(Range)(Range r1, Range r2) @trusted
+if (isInputRange!Range && hasLvalueElements!Range)
+{
+    return &r1.front is &r2.front;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    const int[2] array;
+
+    auto r1 = array[];
+    auto r2 = array[];
+
+    assert(sameHead(r1, r2));
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    const int[2] array;
+
+    auto r1 = array[];
+    auto r2 = array[1 .. $];
+
+    assert(!sameHead(r1, r2));
+}

source/tanya/sys/linux/syscall.d

@@ -14,9 +14,15 @@ module tanya.sys.linux.syscall;
 
 version (TanyaNative):
 
+extern ptrdiff_t syscall(ptrdiff_t, ptrdiff_t)
+@nogc nothrow @system;
+
 extern ptrdiff_t syscall(ptrdiff_t, ptrdiff_t, ptrdiff_t)
 @nogc nothrow @system;
 
+extern ptrdiff_t syscall(ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t)
+@nogc nothrow @system;
+
 extern ptrdiff_t syscall(ptrdiff_t,
                          ptrdiff_t,
                          ptrdiff_t,
@@ -34,10 +40,18 @@ private template getOverloadMangling(size_t n)
 }
 
 pragma(mangle, getOverloadMangling!0)
-extern ptrdiff_t syscall_(ptrdiff_t, ptrdiff_t, ptrdiff_t)
+extern ptrdiff_t syscall_(ptrdiff_t, ptrdiff_t)
 @nogc nothrow pure @system;
 
 pragma(mangle, getOverloadMangling!1)
+extern ptrdiff_t syscall_(ptrdiff_t, ptrdiff_t, ptrdiff_t)
+@nogc nothrow pure @system;
+
+pragma(mangle, getOverloadMangling!2)
+extern ptrdiff_t syscall_(ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t)
+@nogc nothrow pure @system;
+
+pragma(mangle, getOverloadMangling!3)
 extern ptrdiff_t syscall_(ptrdiff_t,
                           ptrdiff_t,
                           ptrdiff_t,

source/tanya/sys/posix/ioctl.d

@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/posix/ioctl.d,
+ *                 tanya/sys/posix/ioctl.d)
+ */
+module tanya.sys.posix.ioctl;
+
+version (TanyaNative):
+
+enum
+{
+    SIOCADDRT = 0x890B, // Add routing table entry.
+    SIOCDELRT = 0x890C, // Delete routing table entry.
+    SIOCRTMSG = 0x890D, // Call to routing system.
+
+    SIOCGIFNAME = 0x8910, // Get iface name.
+    SIOCSIFLINK = 0x8911, // Set iface channel.
+    SIOCGIFCONF = 0x8912, // Get iface list.
+    SIOCGIFFLAGS = 0x8913, // Get flags.
+    SIOCSIFFLAGS = 0x8914, // Set flags.
+    SIOCGIFADDR = 0x8915, // Get PA address.
+    SIOCSIFADDR = 0x8916, // Set PA address.
+    SIOCGIFDSTADDR = 0x8917, // Get remote PA address.
+    SIOCSIFDSTADDR = 0x8918, // Set remote PA address.
+    SIOCGIFBRDADDR = 0x8919, // Get broadcast PA address.
+    SIOCSIFBRDADDR = 0x891a, // Set broadcast PA address.
+    SIOCGIFNETMASK = 0x891b, // Get network PA mask.
+    SIOCSIFNETMASK = 0x891c, // Set network PA mask.
+    SIOCGIFMETRIC = 0x891d, // Get metric.
+    SIOCSIFMETRIC = 0x891e, // Set metric.
+    SIOCGIFMEM = 0x891f, // Get memory address (BSD).
+    SIOCSIFMEM = 0x8920, // Set memory address (BSD).
+    SIOCGIFMTU = 0x8921, // Get MTU size.
+    SIOCSIFMTU = 0x8922, // Set MTU size.
+    SIOCSIFNAME = 0x8923, // Set interface name.
+    SIOCSIFHWADDR = 0x8924, // Set hardware address.
+    SIOCGIFENCAP = 0x8925, // Get/set encapsulations.
+    SIOCSIFENCAP = 0x8926,
+    SIOCGIFHWADDR = 0x8927, // Get hardware address.
+    SIOCGIFSLAVE = 0x8929, // Driver slaving support.
+    SIOCSIFSLAVE = 0x8930,
+    SIOCADDMULTI = 0x8931, // Multicast address lists.
+    SIOCDELMULTI = 0x8932,
+    SIOCGIFINDEX = 0x8933, // Name -> if_index mapping.
+    SIOGIFINDEX = SIOCGIFINDEX, // Misprint compatibility.
+    SIOCSIFPFLAGS = 0x8934, // Set/get extended flags set.
+    SIOCGIFPFLAGS = 0x8935,
+    SIOCDIFADDR = 0x8936, // Delete PA address.
+    SIOCSIFHWBROADCAST = 0x8937, // Set hardware broadcast address.
+    SIOCGIFCOUNT = 0x8938, // Get number of devices.
+
+    SIOCGIFBR = 0x8940, // Bridging support.
+    SIOCSIFBR = 0x8941, // Set bridging options.
+
+    SIOCGIFTXQLEN = 0x8942, // Get the tx queue length.
+    SIOCSIFTXQLEN = 0x8943, // Set the tx queue length.
+
+    SIOCDARP = 0x8953, // Delete ARP table entry.
+    SIOCGARP = 0x8954, // Get ARP table entry.
+    SIOCSARP = 0x8955, // Set ARP table entry.
+
+    SIOCDRARP = 0x8960, // Delete RARP table entry.
+    SIOCGRARP = 0x8961, // Get RARP table entry.
+    SIOCSRARP = 0x8962, // Set RARP table entry.
+
+    SIOCGIFMAP = 0x8970, // Get device parameters.
+    SIOCSIFMAP = 0x8971, // Set device parameters.
+
+    SIOCADDDLCI = 0x8980, // Create new DLCI device.
+    SIOCDELDLCI = 0x8981, // Delete DLCI device.
+}

source/tanya/sys/posix/net/if_.d

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/posix/net/if_.d,
+ *                 tanya/sys/posix/net/if_.d)
+ */
+module tanya.sys.posix.net.if_;
+
+version (TanyaNative):
+
+enum size_t IF_NAMESIZE = 16;
+
+struct ifreq
+{
+    char[IF_NAMESIZE] ifr_name;
+
+    union
+    {
+        int ifr_ifindex;
+    }
+}

source/tanya/sys/posix/socket.d

@@ -0,0 +1,152 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/posix/socket.d,
+ *                 tanya/sys/posix/socket.d)
+ */
+module tanya.sys.posix.socket;
+
+version (TanyaNative):
+
+/*
+ * Protocol families.
+ */
+enum
+{
+    PF_UNSPEC = 0, // Unspecified.
+    PF_LOCAL = 1, // Local to host (pipes and file-domain).
+    PF_UNIX = PF_LOCAL, // POSIX name for PF_LOCAL.
+    PF_FILE = PF_LOCAL, // Another non-standard name for PF_LOCAL.
+    PF_INET = 2, // IP protocol family.
+    PF_AX25 = 3, // Amateur Radio AX.25.
+    PF_IPX = 4, // Novell Internet Protocol.
+    PF_APPLETALK = 5, // Appletalk DDP.
+    PF_NETROM = 6, // Amateur radio NetROM.
+    PF_BRIDGE = 7, // Multiprotocol bridge.
+    PF_ATMPVC = 8, // ATM PVCs.
+    PF_X25 = 9, // Reserved for X.25 project.
+    PF_INET6 = 10, // IP version 6.
+    PF_ROSE = 11, // Amateur Radio X.25 PLP.
+    PF_DECnet = 12, // Reserved for DECnet project.
+    PF_NETBEUI = 13, // Reserved for 802.2LLC project.
+    PF_SECURITY = 14, // Security callback pseudo AF.
+    PF_KEY = 15, // PF_KEY key management API.
+    PF_NETLINK = 16, // Kernel user interface device.
+    PF_ROUTE = PF_NETLINK, // Alias to emulate 4.4BSD.
+    PF_PACKET = 17, // Packet family.
+    PF_ASH = 18, // Ash.
+    PF_ECONET = 19, // Acorn Econet.
+    PF_ATMSVC = 20, // ATM SVCs.
+    PF_RDS = 21, // RDS sockets.
+    PF_SNA = 22, // Linux SNA Project.
+    PF_IRDA = 23, // IRDA sockets.
+    PF_PPPOX = 24, // PPPoX sockets.
+    PF_WANPIPE = 25, // Wanpipe API sockets.
+    PF_LLC = 26, // Linux LLC.
+    PF_IB = 27, // Native InfiniBand address.
+    PF_MPLS = 28, // MPLS.
+    PF_CAN = 29, // Controller Area Network.
+    PF_TIPC = 30, // TIPC sockets.
+    PF_BLUETOOTH = 31, // Bluetooth sockets.
+    PF_IUCV = 32, // IUCV sockets.
+    PF_RXRPC = 33, // RxRPC sockets.
+    PF_ISDN = 34, // mISDN sockets.
+    PF_PHONET = 35, // Phonet sockets.
+    PF_IEEE802154 = 36, // IEEE 802.15.4 sockets.
+    PF_CAIF = 37, // CAIF sockets.
+    PF_ALG = 38, // Algorithm sockets.
+    PF_NFC = 39, // NFC sockets.
+    PF_VSOCK = 40, // vSockets.
+    PF_MAX = 41, // For now.
+}
+
+/*
+ * Address families.
+ */
+enum
+{
+    AF_UNSPEC = PF_UNSPEC,
+    AF_LOCAL = PF_LOCAL,
+    AF_UNIX = PF_UNIX,
+    AF_FILE = PF_FILE,
+    AF_INET = PF_INET,
+    AF_AX25 = PF_AX25,
+    AF_IPX = PF_IPX,
+    AF_APPLETALK = PF_APPLETALK,
+    AF_NETROM = PF_NETROM,
+    AF_BRIDGE = PF_BRIDGE,
+    AF_ATMPVC = PF_ATMPVC,
+    AF_X25 = PF_X25,
+    AF_INET6 = PF_INET6,
+    AF_ROSE = PF_ROSE,
+    AF_DECnet = PF_DECnet,
+    AF_NETBEUI = PF_NETBEUI,
+    AF_SECURITY = PF_SECURITY,
+    AF_KEY = PF_KEY,
+    AF_NETLINK = PF_NETLINK,
+    AF_ROUTE = PF_ROUTE,
+    AF_PACKET = PF_PACKET,
+    AF_ASH = PF_ASH,
+    AF_ECONET = PF_ECONET,
+    AF_ATMSVC = PF_ATMSVC,
+    AF_RDS = PF_RDS,
+    AF_SNA = PF_SNA,
+    AF_IRDA = PF_IRDA,
+    AF_PPPOX = PF_PPPOX,
+    AF_WANPIPE = PF_WANPIPE,
+    AF_LLC = PF_LLC,
+    AF_IB = PF_IB,
+    AF_MPLS = PF_MPLS,
+    AF_CAN = PF_CAN,
+    AF_TIPC = PF_TIPC,
+    AF_BLUETOOTH = PF_BLUETOOTH,
+    AF_IUCV = PF_IUCV,
+    AF_RXRPC = PF_RXRPC,
+    AF_ISDN = PF_ISDN,
+    AF_PHONET = PF_PHONET,
+    AF_IEEE802154 = PF_IEEE802154,
+    AF_CAIF = PF_CAIF,
+    AF_ALG = PF_ALG,
+    AF_NFC = PF_NFC,
+    AF_VSOCK = PF_VSOCK,
+    AF_MAX = PF_MAX,
+}
+
+/*
+ * Types of sockets.
+ */
+enum
+{
+    // Sequenced, reliable, connection-based byte streams.
+    SOCK_STREAM = 1,
+    // Connectionless, unreliable datagrams of fixed maximum length.
+    SOCK_DGRAM = 2,
+    // Raw protocol interface.
+    SOCK_RAW = 3,
+    // Reliably-delivered messages.
+    SOCK_RDM = 4,
+    // Sequenced, reliable, connection-based, datagrams of fixed maximum
+    // length.
+    SOCK_SEQPACKET = 5,
+    // Datagram Congestion Control Protocol.
+    SOCK_DCCP = 6,
+    // Linux specific way of getting packets at the dev level. For writing rarp
+    // and other similar things on the user level.
+    SOCK_PACKET = 10,
+}
+
+/*
+ * Flags to be ORed into the type parameter of socket and socketpair and used
+ * for the flags parameter of paccept.
+ */
+enum
+{
+    SOCK_CLOEXEC = 0x80000, // Atomically set close-on-exec flag for the new descriptor(s).
+    SOCK_NONBLOCK = 0x800, // Atomically mark descriptor(s) as non-blocking.
+}

source/tanya/sys/windows/def.d

@@ -16,7 +16,7 @@
  * defined here.
  * Also aliases for specific types like $(D_PSYMBOL SOCKET) are defined here.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -30,6 +30,7 @@ version (Windows):
 alias BYTE = ubyte;
 alias TBYTE = wchar; // If Unicode, otherwise char.
 alias CHAR = char; // Signed or unsigned char.
+alias WCHAR = wchar;
 alias TCHAR = wchar; // If Unicode, otherwise char.
 alias SHORT = short;
 alias USHORT = ushort;
@@ -52,10 +53,14 @@ enum HANDLE INVALID_HANDLE_VALUE = cast(HANDLE) -1;
 enum TRUE = 1;
 enum FALSE = 0;
 
+alias PSTR = CHAR*;
+alias PWSTR = WCHAR*;
+alias PTSTR = TCHAR*;
+
 align(1) struct GUID
 {
     uint Data1;
     ushort Data2;
     ushort Data3;
     char[8] Data4;
-}
+}

source/tanya/sys/windows/error.d

@@ -1,115 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/**
- * Copyright: Eugene Wissner 2017.
- * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
- *                  Mozilla Public License, v. 2.0).
- * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
- * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/windows/error.d,
- *                 tanya/sys/windows/error.d)
- */
- deprecated("Use core.sys.windows.winerror instead")
-module tanya.sys.windows.error;
-
-version (Windows):
-
-private enum WSABASEERR = 10000;
-enum
-{
-    WSAEINTR = WSABASEERR + 4,
-    WSAEBADF = WSABASEERR + 9,
-    WSAEACCES = WSABASEERR + 13,
-    WSAEFAULT = WSABASEERR + 14,
-    WSAEINVAL = WSABASEERR + 22,
-    WSAEMFILE = WSABASEERR + 24,
-
-    WSAEWOULDBLOCK = WSABASEERR + 35,
-    WSAEINPROGRESS = WSABASEERR + 36,
-    WSAEALREADY = WSABASEERR + 37,
-    WSAENOTSOCK = WSABASEERR + 38,
-    WSAEDESTADDRREQ = WSABASEERR + 39,
-    WSAEMSGSIZE = WSABASEERR + 40,
-    WSAEPROTOTYPE = WSABASEERR + 41,
-    WSAENOPROTOOPT = WSABASEERR + 42,
-    WSAEPROTONOSUPPORT = WSABASEERR + 43,
-    WSAESOCKTNOSUPPORT = WSABASEERR + 44,
-    WSAEOPNOTSUPP = WSABASEERR + 45,
-    WSAEPFNOSUPPORT = WSABASEERR + 46,
-    WSAEAFNOSUPPORT = WSABASEERR + 47,
-    WSAEADDRINUSE = WSABASEERR + 48,
-    WSAEADDRNOTAVAIL = WSABASEERR + 49,
-    WSAENETDOWN = WSABASEERR + 50,
-    WSAENETUNREACH = WSABASEERR + 51,
-    WSAENETRESET = WSABASEERR + 52,
-    WSAECONNABORTED = WSABASEERR + 53,
-    WSAECONNRESET = WSABASEERR + 54,
-    WSAENOBUFS = WSABASEERR + 55,
-    WSAEISCONN = WSABASEERR + 56,
-    WSAENOTCONN = WSABASEERR + 57,
-    WSAESHUTDOWN = WSABASEERR + 58,
-    WSAETOOMANYREFS = WSABASEERR + 59,
-    WSAETIMEDOUT = WSABASEERR + 60,
-    WSAECONNREFUSED = WSABASEERR + 61,
-    WSAELOOP = WSABASEERR + 62,
-    WSAENAMETOOLONG = WSABASEERR + 63,
-    WSAEHOSTDOWN = WSABASEERR + 64,
-    WSAEHOSTUNREACH = WSABASEERR + 65,
-    WSAENOTEMPTY = WSABASEERR + 66,
-    WSAEPROCLIM = WSABASEERR + 67,
-    WSAEUSERS = WSABASEERR + 68,
-    WSAEDQUOT = WSABASEERR + 69,
-    WSAESTALE = WSABASEERR + 70,
-    WSAEREMOTE = WSABASEERR + 71,
-
-    WSASYSNOTREADY = WSABASEERR + 91,
-    WSAVERNOTSUPPORTED = WSABASEERR + 92,
-    WSANOTINITIALISED = WSABASEERR + 93,
-    WSAEDISCON = WSABASEERR + 101,
-    WSAENOMORE = WSABASEERR + 102,
-    WSAECANCELLED = WSABASEERR + 103,
-    WSAEINVALIDPROCTABLE = WSABASEERR + 104,
-    WSAEINVALIDPROVIDER = WSABASEERR + 105,
-    WSAEPROVIDERFAILEDINIT = WSABASEERR + 106,
-    WSASYSCALLFAILURE = WSABASEERR + 107,
-    WSASERVICE_NOT_FOUND = WSABASEERR + 108,
-    WSATYPE_NOT_FOUND = WSABASEERR + 109,
-    WSA_E_NO_MORE = WSABASEERR + 110,
-    WSA_E_CANCELLED = WSABASEERR + 111,
-    WSAEREFUSED = WSABASEERR + 112,
-
-    WSAHOST_NOT_FOUND = WSABASEERR + 1001,
-    WSATRY_AGAIN = WSABASEERR + 1002,
-    WSANO_RECOVERY = WSABASEERR + 1003,
-    WSANO_DATA = WSABASEERR + 1004,
-
-    WSA_QOS_RECEIVERS = WSABASEERR + 1005,
-    WSA_QOS_SENDERS = WSABASEERR + 1006,
-    WSA_QOS_NO_SENDERS = WSABASEERR + 1007,
-    WSA_QOS_NO_RECEIVERS = WSABASEERR + 1008,
-    WSA_QOS_REQUEST_CONFIRMED = WSABASEERR + 1009,
-    WSA_QOS_ADMISSION_FAILURE = WSABASEERR + 1010,
-    WSA_QOS_POLICY_FAILURE = WSABASEERR + 1011,
-    WSA_QOS_BAD_STYLE = WSABASEERR + 1012,
-    WSA_QOS_BAD_OBJECT = WSABASEERR + 1013,
-
-    WSA_QOS_TRAFFIC_CTRL_ERROR = WSABASEERR + 1014,
-    WSA_QOS_GENERIC_ERROR = WSABASEERR + 1015,
-    WSA_QOS_ESERVICETYPE = WSABASEERR + 1016,
-    WSA_QOS_EFLOWSPEC = WSABASEERR + 1017,
-    WSA_QOS_EPROVSPECBUF = WSABASEERR + 1018,
-    WSA_QOS_EFILTERSTYLE = WSABASEERR + 1019,
-    WSA_QOS_EFILTERTYPE = WSABASEERR + 1020,
-    WSA_QOS_EFILTERCOUNT = WSABASEERR + 1021,
-    WSA_QOS_EOBJLENGTH = WSABASEERR + 1022,
-    WSA_QOS_EFLOWCOUNT = WSABASEERR + 1023,
-    WSA_QOS_EUNKOWNPSOBJ = WSABASEERR + 1024,
-    WSA_QOS_EPOLICYOBJ = WSABASEERR + 1025,
-    WSA_QOS_EFLOWDESC = WSABASEERR + 1026,
-    WSA_QOS_EPSFLOWSPEC = WSABASEERR + 1027,
-    WSA_QOS_EPSFILTERSPEC = WSABASEERR + 1028,
-    WSA_QOS_ESDMODEOBJ = WSABASEERR + 1029,
-    WSA_QOS_ESHAPERATEOBJ = WSABASEERR + 1030,
-    WSA_QOS_RESERVED_PETYPE = WSABASEERR + 1031,
-}

source/tanya/sys/windows/ifdef.d

@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/windows/ifdef.d,
+ *                 tanya/sys/windows/ifdef.d)
+ */
+module tanya.sys.windows.ifdef;
+
+version (Windows):
+
+import tanya.sys.windows.def;
+
+union NET_LUID_LH
+{
+    ulong Value;
+    ulong Info;
+}
+
+alias NET_LUID = NET_LUID_LH;
+alias IF_LUID = NET_LUID_LH;
+
+alias NET_IFINDEX = ULONG;
+
+enum size_t IF_MAX_STRING_SIZE = 256;

source/tanya/sys/windows/iphlpapi.d

@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/sys/windows/iphlpapi.d,
+ *                 tanya/sys/windows/iphlpapi.d)
+ */
+module tanya.sys.windows.iphlpapi;
+
+version (Windows):
+
+import tanya.sys.windows.def;
+import tanya.sys.windows.ifdef;
+
+extern(Windows)
+DWORD ConvertInterfaceNameToLuidA(const(CHAR)* InterfaceName,
+                                  NET_LUID* InterfaceLuid)
+@nogc nothrow @system;
+
+extern(Windows)
+DWORD ConvertInterfaceLuidToIndex(const(NET_LUID)* InterfaceLuid,
+                                  NET_IFINDEX* InterfaceIndex)
+@nogc nothrow @system;
+
+extern(Windows)
+DWORD ConvertInterfaceIndexToLuid(NET_IFINDEX InterfaceIndex,
+                                  NET_LUID* InterfaceLuid)
+@nogc nothrow @system;
+
+extern(Windows)
+DWORD ConvertInterfaceLuidToNameA(const(NET_LUID)* InterfaceLuid,
+                                  PSTR InterfaceName,
+                                  size_t Length)
+@nogc nothrow @system;

source/tanya/sys/windows/package.d

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -15,6 +15,7 @@ module tanya.sys.windows;
 version (Windows):
 
 public import tanya.sys.windows.def;
-public import tanya.sys.windows.error;
+public import tanya.sys.windows.ifdef;
+public import tanya.sys.windows.iphlpapi;
 public import tanya.sys.windows.winbase;
-public import tanya.sys.windows.winsock2;
+public import tanya.sys.windows.winsock2;

source/tanya/sys/windows/winbase.d

@@ -5,7 +5,7 @@
 /**
  * Definitions from winbase.h.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -52,4 +52,4 @@ extern(Windows)
 BOOL GetOverlappedResult(HANDLE hFile,
                          OVERLAPPED* lpOverlapped,
                          DWORD* lpNumberOfBytesTransferred,
-                         BOOL bWait) nothrow @system @nogc;
+                         BOOL bWait) nothrow @system @nogc;

source/tanya/sys/windows/winsock2.d

@@ -5,7 +5,7 @@
 /**
  * Definitions from winsock2.h, ws2def.h and MSWSock.h.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -216,4 +216,4 @@ enum
     SO_UPDATE_ACCEPT_CONTEXT = 0x700B,
     SO_CONNECT_TIME = 0x700C,
     SO_UPDATE_CONNECT_CONTEXT = 0x7010,
-}
+}

source/tanya/test/assertion.d

@@ -13,7 +13,7 @@
  * The functions can cause segmentation fault if the module is compiled
  * in production mode and the condition fails.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)

source/tanya/test/package.d

@@ -5,7 +5,7 @@
 /**
  * Test suite for $(D_KEYWORD unittest)-blocks.
  *
- * Copyright: Eugene Wissner 2017.
+ * Copyright: Eugene Wissner 2017-2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -15,3 +15,4 @@
 module tanya.test;
 
 public import tanya.test.assertion;
+public import tanya.test.stub;

source/tanya/test/stub.d

@@ -0,0 +1,373 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Range and generic type generators.
+ *
+ * Copyright: Eugene Wissner 2018.
+ * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
+ *                  Mozilla Public License, v. 2.0).
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
+ * Source: $(LINK2 https://github.com/caraus-ecms/tanya/blob/master/source/tanya/test/stub.d,
+ *                 tanya/test/stub.d)
+ */
+module tanya.test.stub;
+
+/**
+ * Attribute signalizing that the generated range should contain the given
+ * number of elements.
+ *
+ * $(D_PSYMBOL Count) should be always specified with some value and not as a
+ * type, so $(D_INLINECODE Count(1)) instead just $(D_INLINECODE Count),
+ * otherwise you can just omit $(D_PSYMBOL Count) and it will default to 0.
+ *
+ * $(D_PSYMBOL Count) doesn't generate `.length` property - use
+ * $(D_PSYMBOL Length) for that.
+ *
+ * If neither $(D_PSYMBOL Length) nor $(D_PSYMBOL Infinite) is given,
+ * $(D_ILNINECODE Count(0)) is assumed.
+ *
+ * This attribute conflicts with $(D_PSYMBOL Infinite) and $(D_PSYMBOL Length).
+ */
+struct Count
+{
+    /// Original range length.
+    size_t count = 0;
+
+    @disable this();
+
+    /**
+     * Constructs the attribute with the given length.
+     *
+     * Params:
+     *  count = Original range length.
+     */
+    this(size_t count) @nogc nothrow pure @safe
+    {
+        this.count = count;
+    }
+}
+
+/**
+ * Attribute signalizing that the generated range should be infinite.
+ *
+ * This attribute conflicts with $(D_PSYMBOL Count) and $(D_PSYMBOL Length).
+ */
+struct Infinite
+{
+}
+
+/**
+ * Generates `.length` property for the range.
+ *
+ * The length of the range can be specified as a constructor argument,
+ * otherwise it is 0.
+ *
+ * This attribute conflicts with $(D_PSYMBOL Count) and $(D_PSYMBOL Infinite).
+ */
+struct Length
+{
+    /// Original range length.
+    size_t length = 0;
+}
+
+/**
+ * Attribute signalizing that the generated range should return values by
+ * reference.
+ *
+ * This atribute affects the return values of `.front`, `.back` and `[]`.
+ */
+struct WithLvalueElements
+{
+}
+
+/**
+ * Generates an input range.
+ *
+ * Params:
+ *  E = Element type.
+ */
+mixin template InputRangeStub(E = int)
+{
+    import tanya.meta.metafunction : Alias;
+    import tanya.meta.trait : evalUDA, getUDAs, hasUDA;
+
+    /*
+     * Aliases for the attribute lookups to access them faster
+     */
+    private enum bool infinite = hasUDA!(typeof(this), Infinite);
+    private enum bool withLvalueElements = hasUDA!(typeof(this),
+                                                   WithLvalueElements);
+    private alias Count = getUDAs!(typeof(this), .Count);
+    private alias Length = getUDAs!(typeof(this), .Length);
+
+    static if (Count.length != 0)
+    {
+        private enum size_t count = Count[0].count;
+
+        static assert (!infinite,
+                       "Range cannot have count and be infinite at the same time");
+        static assert (Length.length == 0,
+                       "Range cannot have count and length at the same time");
+    }
+    else static if (Length.length != 0)
+    {
+        private enum size_t count = evalUDA!(Length[0]).length;
+
+        static assert (!infinite,
+                       "Range cannot have length and be infinite at the same time");
+    }
+    else static if (!infinite)
+    {
+        private enum size_t count = 0;
+    }
+
+    /*
+     * Member generation
+     */
+    static if (infinite)
+    {
+        enum bool empty = false;
+    }
+    else
+    {
+        private size_t length_ = count;
+
+        @property bool empty() const @nogc nothrow pure @safe
+        {
+            return this.length_ == 0;
+        }
+    }
+
+    static if (withLvalueElements)
+    {
+        private E* element; // Pointer to enable range copying in save()
+    }
+
+    void popFront() @nogc nothrow pure @safe
+    in (!empty)
+    {
+        static if (!infinite)
+        {
+            --this.length_;
+        }
+    }
+
+    static if (withLvalueElements)
+    {
+        ref E front() @nogc nothrow pure @safe
+        in (!empty)
+        {
+            return *this.element;
+        }
+    }
+    else
+    {
+        E front() @nogc nothrow pure @safe
+        in (!empty)
+        {
+            return E.init;
+        }
+    }
+
+    static if (Length.length != 0)
+    {
+        size_t length() const @nogc nothrow pure @safe
+        {
+            return this.length_;
+        }
+    }
+}
+
+/**
+ * Generates a forward range.
+ *
+ * This mixin includes input range primitives as well, but can be combined with
+ * $(D_PSYMBOL RandomAccessRangeStub).
+ *
+ * Params:
+ *  E = Element type.
+ */
+mixin template ForwardRangeStub(E = int)
+{
+    static if (!is(typeof(this.InputRangeMixin) == void))
+    {
+        mixin InputRangeStub!E InputRangeMixin;
+    }
+
+    auto save() @nogc nothrow pure @safe
+    {
+        return this;
+    }
+}
+
+/**
+ * Generates a bidirectional range.
+ *
+ * This mixin includes forward range primitives as well, but can be combined with
+ * $(D_PSYMBOL RandomAccessRangeStub).
+ *
+ * Params:
+ *  E = Element type.
+ */
+mixin template BidirectionalRangeStub(E = int)
+{
+    mixin ForwardRangeStub!E;
+
+    void popBack() @nogc nothrow pure @safe
+    in (!empty)
+    {
+        static if (!infinite)
+        {
+            --this.length_;
+        }
+    }
+
+    static if (withLvalueElements)
+    {
+        ref E back() @nogc nothrow pure @safe
+        in (!empty)
+        {
+            return *this.element;
+        }
+    }
+    else
+    {
+        E back() @nogc nothrow pure @safe
+        in (!empty)
+        {
+            return E.init;
+        }
+    }
+}
+
+/**
+ * Generates a random-access range.
+ *
+ * This mixin includes input range primitives as well, but can be combined with
+ * $(D_PSYMBOL ForwardRangeStub) or $(D_PSYMBOL BidirectionalRangeStub).
+ *
+ * Note that a random-access range also requires $(D_PSYMBOL Length) or
+ * $(D_PARAM Infinite) by definition.
+ *
+ * Params:
+ *  E = Element type.
+ */
+mixin template RandomAccessRangeStub(E = int)
+{
+    static if (!is(typeof(this.InputRangeMixin) == void))
+    {
+        mixin InputRangeStub!E InputRangeMixin;
+    }
+
+    static if (withLvalueElements)
+    {
+        ref E opIndex(size_t) @nogc nothrow pure @safe
+        {
+            return *this.element;
+        }
+    }
+    else
+    {
+        E opIndex(size_t) @nogc nothrow pure @safe
+        {
+            return E.init;
+        }
+    }
+}
+
+/**
+ * Struct with a disabled postblit constructor.
+ *
+ * $(D_PSYMBOL NonCopyable) can be used as an attribute for
+ * $(D_PSYMBOL StructStub) or as a standalone type.
+ */
+struct NonCopyable
+{
+    @disable this(this);
+}
+
+/**
+ * Struct with an elaborate destructor.
+ *
+ * $(D_PSYMBOL WithDtor) can be used as an attribute for
+ * $(D_PSYMBOL StructStub) or as a standalone type.
+ *
+ * When used as a standalone object the constructor of $(D_PSYMBOL WithDtor)
+ * accepts an additional `counter` argument, which is incremented by the
+ * destructor. $(D_PSYMBOL WithDtor) stores a pointer to the passed variable,
+ * so the variable can be investigated after the struct isn't available
+ * anymore.
+ */
+struct WithDtor
+{
+    size_t* counter;
+
+    this(ref size_t counter) @nogc nothrow pure @trusted
+    {
+        this.counter = &counter;
+    }
+
+    ~this() @nogc nothrow pure @safe
+    {
+        if (this.counter !is null)
+        {
+            ++*this.counter;
+        }
+    }
+}
+
+/**
+ * Struct supporting hashing.
+ *
+ * $(D_PSYMBOL Hashable) can be used as an attribute for
+ * $(D_PSYMBOL StructStub) or as a standalone type.
+ *
+ * The constructor accepts an additional parameter, which is returned by the
+ * `toHash()`-function. `0U` is returned if no hash value is given.
+ */
+struct Hashable
+{
+    size_t hash;
+
+    size_t toHash() const @nogc nothrow pure @safe
+    {
+        return this.hash;
+    }
+}
+
+/**
+ * Generates a $(D_KEYWORD struct) with common functionality.
+ *
+ * To specify the needed functionality use user-defined attributes on the
+ * $(D_KEYWORD struct) $(D_PSYMBOL StructStub) is mixed in.
+ *
+ * Supported attributes are: $(D_PSYMBOL NonCopyable), $(D_PSYMBOL Hashable),
+ * $(D_PSYMBOL WithDtor).
+ */
+mixin template StructStub()
+{
+    import tanya.meta.trait : evalUDA, getUDAs, hasUDA;
+
+    static if (hasUDA!(typeof(this), NonCopyable))
+    {
+        @disable this(this);
+    }
+
+    private alias Hashable = getUDAs!(typeof(this), .Hashable);
+    static if (Hashable.length > 0)
+    {
+        size_t toHash() const @nogc nothrow pure @safe
+        {
+            return evalUDA!(Hashable[0]).hash;
+        }
+    }
+
+    static if (hasUDA!(typeof(this), WithDtor))
+    {
+        ~this() @nogc nothrow pure @safe
+        {
+        }
+    }
+}

source/tanya/typecons.d

@@ -8,7 +8,7 @@
  * This module contains templates that allow to build new types from the
  * available ones.
  *
- * Copyright: Eugene Wissner 2017-2018.
+ * Copyright: Eugene Wissner 2017-2019.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -17,71 +17,19 @@
  */
 module tanya.typecons;
 
-import tanya.meta.metafunction : AliasSeq, AliasTuple = Tuple, Map;
-
-deprecated("Use tanya.typecons.Tuple instead")
-template Pair(Specs...)
-{
-    template parseSpecs(size_t fieldCount, Specs...)
-    {
-        static if (Specs.length == 0)
-        {
-            alias parseSpecs = AliasSeq!();
-        }
-        else static if (is(Specs[0]) && fieldCount < 2)
-        {
-            static if (is(typeof(Specs[1]) == string))
-            {
-                alias parseSpecs
-                    = AliasSeq!(AliasTuple!(Specs[0], Specs[1]),
-                                parseSpecs!(fieldCount + 1, Specs[2 .. $]));
-            }
-            else
-            {
-                alias parseSpecs
-                    = AliasSeq!(AliasTuple!(Specs[0]),
-                                parseSpecs!(fieldCount + 1, Specs[1 .. $]));
-            }
-        }
-        else
-        {
-            static assert(false, "Invalid argument: " ~ Specs[0].stringof);
-        }
-    }
-
-    alias ChooseType(alias T) = T.Seq[0];
-    alias ParsedSpecs = parseSpecs!(0, Specs);
-
-    static assert(ParsedSpecs.length == 2, "Invalid argument count");
-
-    struct Pair
-    {
-        /// Field types.
-        alias Types = Map!(ChooseType, ParsedSpecs);
-
-        // Create field aliases.
-        static if (ParsedSpecs[0].length == 2)
-        {
-            mixin("alias " ~ ParsedSpecs[0][1] ~ " = expand[0];");
-        }
-        static if (ParsedSpecs[1].length == 2)
-        {
-            mixin("alias " ~ ParsedSpecs[1][1] ~ " = expand[1];");
-        }
-
-        /// Represents the values of the $(D_PSYMBOL Pair) as a list of values.
-        Types expand;
-
-        alias expand this;
-    }
-}
+import tanya.algorithm.mutation;
+import tanya.conv;
+import tanya.format;
+import tanya.functional;
+import tanya.meta.metafunction;
+import tanya.meta.trait;
+version (unittest) import tanya.test.stub;
 
 /**
- * $(D_PSYMBOL Tuple) can store two heterogeneous objects.
+ * $(D_PSYMBOL Tuple) can store two or more heterogeneous objects.
  *
- * The objects can by accessed by index as $(D_INLINECODE obj[0]) and
- * $(D_INLINECODE obj[1]) or by optional names (e.g.
- * $(D_INLINECODE obj.first)).
+ * The objects can by accessed by index as `obj[0]` and `obj[1]` or by optional
+ * names (e.g. `obj.first`).
  *
  * $(D_PARAM Specs) contains a list of object types and names. First
  * comes the object type, then an optional string containing the name.
@@ -90,6 +38,8 @@ template Pair(Specs...)
  *
  * Params:
  *  Specs = Field types and names.
+ *
+ * See_Also: $(D_PSYMBOL tuple).
  */
 template Tuple(Specs...)
 {
@@ -104,13 +54,13 @@ template Tuple(Specs...)
             static if (is(typeof(Specs[1]) == string))
             {
                 alias parseSpecs
-                    = AliasSeq!(AliasTuple!(Specs[0], Specs[1]),
+                    = AliasSeq!(Pack!(Specs[0], Specs[1]),
                                 parseSpecs!(fieldCount + 1, Specs[2 .. $]));
             }
             else
             {
                 alias parseSpecs
-                    = AliasSeq!(AliasTuple!(Specs[0]),
+                    = AliasSeq!(Pack!(Specs[0]),
                                 parseSpecs!(fieldCount + 1, Specs[1 .. $]));
             }
         }
@@ -123,7 +73,26 @@ template Tuple(Specs...)
     alias ChooseType(alias T) = T.Seq[0];
     alias ParsedSpecs = parseSpecs!(0, Specs);
 
-    static assert(ParsedSpecs.length == 2, "Invalid argument count");
+    static assert(ParsedSpecs.length > 1, "Invalid argument count");
+
+    private string formatAliases(size_t n, Specs...)()
+    {
+        static if (Specs.length == 0)
+        {
+            return "";
+        }
+        else
+        {
+            string fieldAlias;
+            static if (Specs[0].length == 2)
+            {
+                char[21] buffer;
+                fieldAlias = "alias " ~ Specs[0][1] ~ " = expand["
+                           ~ integral2String(n, buffer).idup ~ "];";
+            }
+            return fieldAlias ~ formatAliases!(n + 1, Specs[1 .. $])();
+        }
+    }
 
     struct Tuple
     {
@@ -131,14 +100,7 @@ template Tuple(Specs...)
         alias Types = Map!(ChooseType, ParsedSpecs);
 
         // Create field aliases.
-        static if (ParsedSpecs[0].length == 2)
-        {
-            mixin("alias " ~ ParsedSpecs[0][1] ~ " = expand[0];");
-        }
-        static if (ParsedSpecs[1].length == 2)
-        {
-            mixin("alias " ~ ParsedSpecs[1][1] ~ " = expand[1];");
-        }
+        mixin(formatAliases!(0, ParsedSpecs[0 .. $])());
 
         /// Represents the values of the $(D_PSYMBOL Tuple) as a list of values.
         Types expand;
@@ -171,4 +133,802 @@ template Tuple(Specs...)
     static assert(!is(Tuple!(int, int, int)));
 
     static assert(!is(Tuple!(int, "first")));
+
+    static assert(!is(Tuple!(int, double, char)));
+    static assert(!is(Tuple!(int, "first", double, "second", char, "third")));
+}
+
+/**
+ * Creates a new $(D_PSYMBOL Tuple).
+ *
+ * Params:
+ *  Names = Field names.
+ *
+ * See_Also: $(D_PSYMBOL Tuple).
+ */
+template tuple(Names...)
+{
+    /**
+     * Creates a new $(D_PSYMBOL Tuple).
+     *
+     * Params:
+     *  Args = Field types.
+     *  args = Field values.
+     *
+     * Returns: Newly created $(D_PSYMBOL Tuple).
+     */
+    auto tuple(Args...)(auto ref Args args)
+    if (Args.length >= Names.length && isTypeTuple!Args)
+    {
+        alias Zipped = ZipWith!(AliasSeq, Pack!Args, Pack!Names);
+        alias Nameless = Args[Names.length .. $];
+
+        return Tuple!(Zipped, Nameless)(forward!args);
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    auto t = tuple!("one", "two")(20, 5);
+    assert(t.one == 20);
+    assert(t.two == 5);
+}
+
+/**
+ * $(D_PSYMBOL Option) is a type that contains an optional value.
+ *
+ * Params:
+ *  T = Type of the encapsulated value.
+ *
+ * See_Also: $(D_PSYMBOL option).
+ */
+struct Option(T)
+{
+    private bool isNothing_ = true;
+    private T value = void;
+
+    /**
+     * Constructs a new option with $(D_PARAM value).
+     *
+     * Params:
+     *  value = Encapsulated value.
+     */
+    this()(ref T value)
+    {
+        this.value = value;
+        this.isNothing_ = false;
+    }
+
+    /// ditto
+    this()(T value) @trusted
+    {
+        moveEmplace(value, this.value);
+        this.isNothing_ = false;
+    }
+
+    /**
+     * Tells if the option is just a value or nothing.
+     *
+     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) contains a nothing,
+     *          $(D_KEYWORD false) if it contains a value.
+     */
+    @property bool isNothing() const
+    {
+        return this.isNothing_;
+    }
+
+    /**
+     * Returns the encapsulated value.
+     *
+     * Returns: Value encapsulated in this $(D_PSYMBOL Option).
+     *
+     * See_Also: $(D_PSYMBOL or).
+     *
+     * Precondition: `!isNothing`.
+     */
+    @property ref inout(T) get() inout
+    in (!isNothing, "Option is nothing")
+    {
+        return this.value;
+    }
+
+    /// ditto
+    deprecated("Call Option.get explicitly instead of relying on alias this")
+    @property ref inout(T) get_() inout
+    in (!isNothing, "Option is nothing")
+    {
+        return this.value;
+    }
+
+    /**
+     * Returns the encapsulated value if available or a default value
+     * otherwise.
+     *
+     * Note that the contained value can be returned by reference only if the
+     * default value is passed by reference as well.
+     *
+     * Params:
+     *  U            = Type of the default value.
+     *  defaultValue = Default value.
+     *
+     * Returns: The value of this $(D_PSYMBOL Option) if available,
+     *          $(D_PARAM defaultValue) otherwise.
+     *
+     * See_Also: $(D_PSYMBOL isNothing), $(D_PSYMBOL get).
+     */
+    @property U or(U)(U defaultValue) inout
+    if (is(U == T) && isCopyable!T)
+    {
+        return isNothing ? defaultValue : this.value;
+    }
+
+    /// ditto
+    @property ref inout(T) or(ref inout(T) defaultValue) inout
+    {
+        return isNothing ? defaultValue : this.value;
+    }
+
+    /**
+     * Casts this $(D_PSYMBOL Option) to $(D_KEYWORD bool).
+     *
+     * An $(D_PSYMBOL Option) is $(D_KEYWORD true) if it contains a value,
+     * ($D_KEYWORD false) if it contains nothing.
+     *
+     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) contains a value,
+     *          ($D_KEYWORD false) if it contains nothing.
+     */
+    bool opCast(U : bool)()
+    {
+        return !isNothing;
+    }
+
+    /**
+     * Compares this $(D_PSYMBOL Option) with $(D_PARAM that).
+     *
+     * If both objects are options of the same type and they don't contain a
+     * value, they are considered equal. If only one of them contains a value,
+     * they aren't equal. Otherwise, the encapsulated values are compared for
+     * equality.
+     *
+     * If $(D_PARAM U) is a type comparable with the type encapsulated by this
+     * $(D_PSYMBOL Option), the value of this $(D_PSYMBOL Option) is compared
+     * with $(D_PARAM that), this $(D_PSYMBOL Option) must have a value then.
+     *
+     * Params:
+     *  U    = Type of the object to compare with.
+     *  that = Object to compare with.
+     *
+     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) and
+     *          $(D_PARAM that) are equal, $(D_KEYWORD false) if not.
+     *
+     * Precondition: `!isNothing` if $(D_PARAM U) is equality comparable with
+     *               $(D_PARAM T).
+     */
+    bool opEquals(U)(auto ref const U that) const
+    if (is(U == Option))
+    {
+        if (!isNothing && !that.isNothing)
+        {
+            return this.value == that.value;
+        }
+        return isNothing == that.isNothing;
+    }
+
+    /// ditto
+    bool opEquals(U)(auto ref const U that) const
+    if (ifTestable!(U, a => a == T.init) && !is(U == Option))
+    in
+    {
+        assert(!isNothing);
+    }
+    do
+    {
+        return get == that;
+    }
+
+    /**
+     * Resets this $(D_PSYMBOL Option) and destroys the contained value.
+     *
+     * $(D_PSYMBOL reset) can be safely called on an $(D_PSYMBOL Option) that
+     * doesn't contain any value.
+     */
+    void reset()
+    {
+        static if (hasElaborateDestructor!T)
+        {
+            destroy(this.value);
+        }
+        this.isNothing_ = true;
+    }
+
+    /**
+     * Assigns a new value.
+     *
+     * Params:
+     *  U    = Type of the new value.
+     *  that = New value.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign(U)(ref U that)
+    if (is(U : T) && !is(U == Option))
+    {
+        this.value = that;
+        this.isNothing_ = false;
+        return this;
+    }
+
+    /// ditto
+    ref typeof(this) opAssign(U)(U that)
+    if (is(U == T))
+    {
+        move(that, this.value);
+        this.isNothing_ = false;
+        return this;
+    }
+
+    /// ditto
+    ref typeof(this) opAssign(U)(ref U that)
+    if (is(U == Option))
+    {
+        if (that.isNothing)
+        {
+            reset();
+        }
+        else
+        {
+            this.value = that.get;
+            this.isNothing_ = false;
+        }
+        return this;
+    }
+
+    /// ditto
+    ref typeof(this) opAssign(U)(U that)
+    if (is(U == Option))
+    {
+        move(that.value, this.value);
+        this.isNothing_ = that.isNothing_;
+        return this;
+    }
+
+    version (D_Ddoc)
+    {
+        /**
+         * If $(D_PARAM T) has a `toHash()` method, $(D_PSYMBOL Option) defines
+         * `toHash()` which returns `T.toHash()` if it is set or 0 otherwise.
+         *
+         * Returns: Hash value.
+         */
+        size_t toHash() const;
+    }
+    else static if (is(typeof(T.init.toHash()) == size_t))
+    {
+        size_t toHash() const
+        {
+            return isNothing ? 0U : this.value.toHash();
+        }
+    }
+
+    alias get_ this;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    Option!int option;
+    assert(option.isNothing);
+    assert(option.or(8) == 8);
+    
+    option = 5;
+    assert(!option.isNothing);
+    assert(option.get == 5);
+    assert(option.or(8) == 5);
+
+    option.reset();
+    assert(option.isNothing);
+}
+
+// Assigns a new value
+@nogc nothrow pure @safe unittest
+{
+    {
+        Option!int option = 5;
+        option = 8;
+        assert(!option.isNothing);
+        assert(option == 8);
+    }
+    {
+        Option!int option;
+        const int newValue = 8;
+        assert(option.isNothing);
+        option = newValue;
+        assert(!option.isNothing);
+        assert(option == newValue);
+    }
+    {
+        Option!int option1;
+        Option!int option2 = 5;
+        assert(option1.isNothing);
+        option1 = option2;
+        assert(!option1.isNothing);
+        assert(option1.get == 5);
+    }
+}
+
+// Constructs with a value passed by reference
+@nogc nothrow pure @safe unittest
+{
+    int i = 5;
+    assert(Option!int(i).get == 5);
+}
+
+// Moving
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(typeof(Option!NonCopyable(NonCopyable()))));
+    // The value cannot be returned by reference because the default value
+    // isn't passed by reference
+    static assert(!is(typeof(Option!DisabledPostblit().or(NonCopyable()))));
+    {
+        NonCopyable notCopyable;
+        static assert(is(typeof(Option!NonCopyable().or(notCopyable))));
+    }
+    {
+        Option!NonCopyable option;
+        assert(option.isNothing);
+        option = NonCopyable();
+        assert(!option.isNothing);
+    }
+    {
+        Option!NonCopyable option;
+        assert(option.isNothing);
+        option = Option!NonCopyable(NonCopyable());
+        assert(!option.isNothing);
+    }
+}
+
+// Cast to bool is done before touching the encapsulated value
+@nogc nothrow pure @safe unittest
+{
+    assert(Option!bool(false));
+}
+
+// Option can be const
+@nogc nothrow pure @safe unittest
+{
+    assert((const Option!int(5)).get == 5);
+    assert((const Option!int()).or(5) == 5);
+}
+
+// Equality
+@nogc nothrow pure @safe unittest
+{
+    assert(Option!int() == Option!int());
+    assert(Option!int(0) != Option!int());
+    assert(Option!int(5) == Option!int(5));
+    assert(Option!int(5) == 5);
+    assert(Option!int(5) == cast(ubyte) 5);
+}
+
+// Returns default value
+@nogc nothrow pure @safe unittest
+{
+    int i = 5;
+    assert(((ref e) => e)(Option!int().or(i)) == 5);
+}
+
+// Implements toHash() for nothing
+@nogc nothrow pure @safe unittest
+{
+    alias OptionT = Option!Hashable;
+    assert(OptionT().toHash() == 0U);
+    assert(OptionT(Hashable(1U)).toHash() == 1U);
+}
+
+// Can assign Option that is nothing
+@nogc nothrow pure @safe unittest
+{
+    auto option1 = Option!int(5);
+    Option!int option2;
+    option1 = option2;
+    assert(option1.isNothing);
+}
+
+/**
+ * Creates a new $(D_PSYMBOL Option).
+ *
+ * Params:
+ *  T     = Option type.
+ *  value = Initial value.
+ *
+ * See_Also: $(D_PSYMBOL Option).
+ */
+Option!T option(T)(auto ref T value)
+{
+    return Option!T(forward!value);
+}
+
+/// ditto
+Option!T option(T)()
+{
+    return Option!T();
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    assert(option!int().isNothing);
+    assert(option(5) == 5);
+}
+
+/**
+ * Type that can hold one of the types listed as its template parameters.
+ *
+ * $(D_PSYMBOL Variant) is a type similar to $(D_KEYWORD union), but
+ * $(D_PSYMBOL Variant) keeps track of the actually used type and throws an
+ * assertion error when trying to access an invalid type at runtime.
+ *
+ * Params:
+ *  Specs = Types this $(D_SPYBMOL Variant) can hold.
+ */
+template Variant(Specs...)
+if (isTypeTuple!Specs && NoDuplicates!Specs.length == Specs.length)
+{
+    union AlignedUnion(Args...)
+    {
+        static if (Args.length > 0)
+        {
+            Args[0] value;
+        }
+        static if (Args.length > 1)
+        {
+            AlignedUnion!(Args[1 .. $]) rest;
+        }
+    }
+
+    private struct VariantAccessorInfo
+    {
+        string accessor;
+        ptrdiff_t tag;
+    }
+
+    template accessor(T, Union)
+    {
+        enum VariantAccessorInfo info = accessorImpl!(T, Union, 1);
+        enum accessor = VariantAccessorInfo("this.values" ~ info.accessor, info.tag);
+    }
+
+    template accessorImpl(T, Union, size_t tag)
+    {
+        static if (is(T == typeof(Union.value)))
+        {
+            enum accessorImpl = VariantAccessorInfo(".value", tag);
+        }
+        else
+        {
+            enum VariantAccessorInfo info = accessorImpl!(T, typeof(Union.rest), tag + 1);
+            enum accessorImpl = VariantAccessorInfo(".rest" ~ info.accessor, info.tag);
+        }
+    }
+
+    struct Variant
+    {
+        /// Types can be present in this $(D_PSYMBOL Variant).
+        alias Types = Specs;
+
+        private ptrdiff_t tag = -1;
+        private AlignedUnion!Types values;
+
+        /**
+         * Constructs this $(D_PSYMBOL Variant) with one of the types supported
+         * in it.
+         *
+         * Params:
+         *  T     = Type of the initial value.
+         *  value = Initial value.
+         */
+        this(T)(ref T value)
+        if (canFind!(T, Types))
+        {
+            copyAssign!T(value);
+        }
+
+        /// ditto
+        this(T)(T value)
+        if (canFind!(T, Types))
+        {
+            moveAssign!T(value);
+        }
+
+        ~this()
+        {
+            reset();
+        }
+
+        this(this)
+        {
+            alias pred(U) = hasElaborateCopyConstructor!(U.Seq[1]);
+            static foreach (Type; Filter!(pred, Enumerate!Types))
+            {
+                if (this.tag == Type.Seq[0])
+                {
+                    get!(Type.Seq[1]).__postblit();
+                }
+            }
+        }
+
+        /**
+         * Tells whether this $(D_PSYMBOL Variant) is initialized.
+         *
+         * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Variant) contains a
+         *          value, $(D_KEYWORD false) otherwise.
+         */
+        bool hasValue() const
+        {
+            return this.tag != -1;
+        }
+
+        /**
+         * Tells whether this $(D_PSYMBOL Variant) holds currently a value of
+         * type $(D_PARAM T).
+         *
+         * Params:
+         *  T = Examined type.
+         *
+         * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Variant) currently
+         *          contains a value of type $(D_PARAM T), $(D_KEYWORD false)
+         *          otherwise.
+         */
+        bool peek(T)() const
+        if (canFind!(T, Types))
+        {
+            return this.tag == staticIndexOf!(T, Types);
+        }
+
+        /**
+         * Returns the underlying value, assuming it is of the type $(D_PARAM T).
+         *
+         * Params:
+         *  T = Type of the value should be returned.
+         *
+         * Returns: The underyling value.
+         *
+         * Precondition: The $(D_PSYMBOL Variant) has a value.
+         *
+         * See_Also: $(D_PSYMBOL peek), $(D_PSYMBOL hasValue).
+         */
+        ref inout(T) get(T)() inout
+        if (canFind!(T, Types))
+        in (this.tag == staticIndexOf!(T, Types), "Variant isn't initialized")
+        {
+            mixin("return " ~ accessor!(T, AlignedUnion!Types).accessor ~ ";");
+        }
+
+        /**
+         * Reassigns the value.
+         *
+         * Params:
+         *  T    = Type of the new value
+         *  that = New value.
+         *
+         * Returns: $(D_KEYWORD this).
+         */
+        ref typeof(this) opAssign(T)(T that)
+        if (canFind!(T, Types))
+        {
+            reset();
+            return moveAssign!T(that);
+        }
+
+        /// ditto
+        ref typeof(this) opAssign(T)(ref T that)
+        if (canFind!(T, Types))
+        {
+            reset();
+            return copyAssign!T(that);
+        }
+
+        private ref typeof(this) moveAssign(T)(ref T that) @trusted
+        {
+            this.tag = staticIndexOf!(T, Types);
+
+            enum string accessorMixin = accessor!(T, AlignedUnion!Types).accessor;
+            moveEmplace(that, mixin(accessorMixin));
+
+            return this;
+        }
+
+        private ref typeof(this) copyAssign(T)(ref T that)
+        {
+            this.tag = staticIndexOf!(T, Types);
+
+            enum string accessorMixin = accessor!(T, AlignedUnion!Types).accessor;
+            emplace!T((() @trusted => (&mixin(accessorMixin))[0 .. 1])(), that);
+
+            return this;
+        }
+
+        private void reset()
+        {
+            alias pred(U) = hasElaborateDestructor!(U.Seq[1]);
+            static foreach (Type; Filter!(pred, Enumerate!Types))
+            {
+                if (this.tag == Type.Seq[0])
+                {
+                    destroy(get!(Type.Seq[1]));
+                }
+            }
+        }
+
+        /**
+         * Returns $(D_PSYMBOL TypeInfo) corresponding to the current type.
+         *
+         * If this $(D_PSYMBOL Variant) isn't initialized, returns
+         * $(D_KEYWORD null).
+         *
+         * Returns: $(D_PSYMBOL TypeInfo) of the current type.
+         */
+        @property TypeInfo type()
+        {
+            static foreach (i, Type; Types)
+            {
+                if (this.tag == i)
+                {
+                    return typeid(Type);
+                }
+            }
+            return null;
+        }
+
+        /**
+         * Compares this $(D_PSYMBOL Variant) with another one with the same
+         * specification for equality.
+         *
+         * $(UL
+         *  $(LI If both hold values of the same type, these values are
+         *       compared.)
+         *  $(LI If they hold values of different types, then the
+         *       $(D_PSYMBOL Variant)s aren't equal.)
+         *  $(LI If only one of them is initialized but another one not, they
+         *       aren't equal.)
+         *  $(LI If neither of them is initialized, they are equal.)
+         * )
+         *
+         * Params:
+         *  that = The $(D_PSYMBOL Variant) to compare with.
+         *
+         * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Variant) is equal to
+         *          $(D_PARAM that), $(D_KEYWORD false) otherwise.
+         */
+        bool opEquals()(auto ref inout Variant that) inout
+        {
+            if (this.tag != that.tag)
+            {
+                return false;
+            }
+            static foreach (i, Type; Types)
+            {
+                if (this.tag == i)
+                {
+                    return get!Type == that.get!Type;
+                }
+            }
+            return true;
+        }
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant = 5;
+    assert(variant.peek!int);
+    assert(variant.get!int == 5);
+
+    variant = 5.4;
+    assert(!variant.peek!int);
+    assert(variant.get!double == 5.4);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant;
+    variant = 5;
+    assert(variant.peek!int);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant;
+    variant = 5.0;
+    assert(!variant.peek!int);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant = 5;
+    assert(variant.get!int == 5);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static assert(is(Variant!(int, float)));
+    static assert(is(Variant!int));
+}
+
+@nogc nothrow pure @safe unittest
+{
+    static struct WithDestructorAndCopy
+    {
+        this(this) @nogc nothrow pure @safe
+        {
+        }
+
+        ~this() @nogc nothrow pure @safe
+        {
+        }
+    }
+    static assert(is(Variant!WithDestructorAndCopy));
+}
+
+// Equality compares the underlying objects
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant1 = 5;
+    Variant!(int, double) variant2 = 5;
+    assert(variant1 == variant2);
+}
+
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant1 = 5;
+    Variant!(int, double) variant2 = 6;
+    assert(variant1 != variant2);
+}
+
+// Differently typed variants aren't equal
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant1 = 5;
+    Variant!(int, double) variant2 = 5.0;
+    assert(variant1 != variant2);
+}
+
+// Uninitialized variants are equal
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, double) variant1, variant2;
+    assert(variant1 == variant2);
+}
+
+// Calls postblit constructor of the active type
+@nogc nothrow pure @safe unittest
+{
+    static struct S
+    {
+        bool called;
+
+        this(this)
+        {
+            this.called = true;
+        }
+    }
+    Variant!(int, S) variant1 = S();
+    auto variant2 = variant1;
+    assert(variant2.get!S.called);
+}
+
+// Variant.type is null if the Variant doesn't have a value
+@nogc nothrow pure @safe unittest
+{
+    Variant!(int, uint) variant;
+    assert(variant.type is null);
+}
+
+// Variant can contain only distinct types
+@nogc nothrow pure @safe unittest
+{
+    static assert(!is(Variant!(int, int)));
 }