range.primitive: Support non copyable elements

... in all ranges.

source/tanya/algorithm/iteration.d

@@ -3,13 +3,13 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Range adapters.
+ * Iteration algorithms.
  *
- * A range adapter wraps another range and modifies the way, how the original
+ * 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 adapters are lazy algorithms, they request the next element of the
+ * All algorithms in this module are lazy, they request the next element of the
- * adapted range on demand.
+ * original range on demand.
  *
  * Copyright: Eugene Wissner 2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,

source/tanya/algorithm/mutation.d

@@ -19,6 +19,7 @@ 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)
 {
@@ -554,10 +555,6 @@ if (isInputRange!Range && hasLvalueElements!Range)
 
 @nogc nothrow pure @safe unittest
 {
-    static struct NonCopyable
-    {
-        @disable this(this);
-    }
     NonCopyable[] nonCopyable;
     initializeAll(nonCopyable);
 }

source/tanya/conv.d

@@ -27,6 +27,7 @@ import tanya.range.primitive;
 version (unittest)
 {
     import tanya.test.assertion;
+    import tanya.test.stub;
 }
 
 /**
@@ -257,32 +258,23 @@ out(result; memory.ptr is result)
 // Can emplace structs without a constructor
 @nogc nothrow pure @safe unittest
 {
-    static struct SWithDtor
+    static assert(is(typeof(emplace!WithDtor(null, WithDtor()))));
-    {
+    static assert(is(typeof(emplace!WithDtor(null))));
-        ~this() @nogc nothrow pure @safe
-        {
-        }
-    }
-    static assert(is(typeof(emplace!SWithDtor(null, SWithDtor()))));
-    static assert(is(typeof(emplace!SWithDtor(null))));
 }
 
 // Doesn't call a destructor on uninitialized elements
 @nogc nothrow pure @system unittest
 {
-    static struct WithDtor
+    static struct SWithDtor
     {
         private bool canBeInvoked = false;
         ~this() @nogc nothrow pure @safe
         {
-            if (!this.canBeInvoked)
+            assert(this.canBeInvoked);
-            {
-                assert(false);
-            }
         }
     }
-    void[WithDtor.sizeof] memory = void;
+    void[SWithDtor.sizeof] memory = void;
-    auto actual = emplace!WithDtor(memory[], WithDtor(true));
+    auto actual = emplace!SWithDtor(memory[], SWithDtor(true));
     assert(actual.canBeInvoked);
 }
 

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;
+    size_t destroyed;
-
-    static struct F
     {
-        ~this() @nogc nothrow @safe
+        auto rc = defaultAllocator.refCounted!WithDtor(destroyed);
-        {
-            destroyed = true;
-        }
     }
-    {
+    assert(destroyed == 1);
-        auto rc = defaultAllocator.refCounted!F();
-    }
-    assert(destroyed);
 }
 
 /**

source/tanya/range/primitive.d

@@ -316,6 +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.
  *
@@ -335,11 +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
     {
@@ -415,6 +435,28 @@ template isInputRange(R)
     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.
  *
@@ -521,11 +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
     {
@@ -591,6 +633,17 @@ template isBidirectionalRange(R)
     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.
  *
@@ -616,11 +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
     {
@@ -731,6 +784,17 @@ 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).
  *
@@ -1698,10 +1762,6 @@ template hasLvalueElements(R)
 // Works with non-copyable elements
 @nogc nothrow pure @safe unittest
 {
-    static struct NonCopyable
-    {
-        @disable this(this);
-    }
     static assert(hasLvalueElements!(NonCopyable[]));
 }
 

source/tanya/test/stub.d

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Range generators.
+ * Range and generic type generators.
  *
  * Copyright: Eugene Wissner 2018.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
@@ -248,6 +248,9 @@ mixin template BidirectionalRangeStub(E = int)
  * 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.
  */
@@ -273,3 +276,37 @@ mixin template RandomAccessRangeStub(E = int)
         }
     }
 }
+
+/**
+ * Struct with a disabled postblit constructor.
+ */
+struct NonCopyable
+{
+    @disable this(this);
+}
+
+/**
+ * Struct with an elaborate destructor.
+ *
+ * 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;
+        }
+    }
+}

source/tanya/typecons.d

@@ -22,6 +22,7 @@ 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 or more heterogeneous objects.
@@ -454,29 +455,24 @@ struct Option(T)
 // Moving
 @nogc nothrow pure @safe unittest
 {
-    static struct NotCopyable
+    static assert(is(typeof(Option!NonCopyable(NonCopyable()))));
-    {
-        @disable this(this);
-    }
-
-    static assert(is(typeof(Option!NotCopyable(NotCopyable()))));
     // The value cannot be returned by reference because the default value
     // isn't passed by reference
-    static assert(!is(typeof(Option!DisabledPostblit().or(NotCopyable()))));
+    static assert(!is(typeof(Option!DisabledPostblit().or(NonCopyable()))));
     {
-        NotCopyable notCopyable;
+        NonCopyable notCopyable;
-        static assert(is(typeof(Option!NotCopyable().or(notCopyable))));
+        static assert(is(typeof(Option!NonCopyable().or(notCopyable))));
     }
     {
-        Option!NotCopyable option;
+        Option!NonCopyable option;
         assert(option.isNothing);
-        option = NotCopyable();
+        option = NonCopyable();
         assert(!option.isNothing);
     }
     {
-        Option!NotCopyable option;
+        Option!NonCopyable option;
         assert(option.isNothing);
-        option = Option!NotCopyable(NotCopyable());
+        option = Option!NonCopyable(NonCopyable());
         assert(!option.isNothing);
     }
 }