Implement pure onOutOfMemory

8 files changed, 451 insertions, 135 deletions

diff --git a/README.md b/README.md
index 0fe83ad..bf3fe7c 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,10 @@ Tanya consists of the following packages and (top-level) modules:
 * `async`: Event loop (epoll, kqueue and IOCP).
 * `container`: Queue, Array, Singly and doubly linked lists, Buffers, UTF-8
 string, Hash set.
+* `conv`: This module provides functions for converting between different
+types.
 * `encoding`: This package provides tools to work with text encodings.
+* `exception`: Common exceptions and errors.
 * `format`: Formatting and conversion functions.
 * `math`: Arbitrary precision integer and a set of functions.
 * `memory`: Tools for manual memory management (allocators, smart pointers).
diff --git a/source/tanya/container/array.d b/source/tanya/container/array.d
index 2b6e5b6..0af61c7 100644
--- a/source/tanya/container/array.d
+++ b/source/tanya/container/array.d
@@ -15,11 +15,10 @@
 module tanya.container.array;
 
 import core.checkedint;
-import core.exception;
 import std.algorithm.comparison;
 import std.algorithm.mutation;
-import std.conv;
 import std.meta;
+import tanya.exception;
 import tanya.memory;
 import tanya.meta.trait;
 import tanya.meta.transform;
@@ -501,7 +500,7 @@ struct Array(T)
             buf = allocator.allocate(byteSize);
             if (buf is null)
             {
-                onOutOfMemoryErrorNoGC();
+                onOutOfMemoryError();
             }
             scope (failure)
             {
@@ -708,9 +707,12 @@ struct Array(T)
     size_t insertBack(R)(ref R el) @trusted
         if (isImplicitlyConvertible!(R, T))
     {
-        reserve(this.length_ + 1);
-        emplace(this.data + this.length_, el);
-        ++this.length_;
+        this.length = this.length + 1;
+        scope (failure)
+        {
+            this.length = this.length - 1;
+        }
+        opIndex(this.length - 1) = el;
         return 1;
     }
 
diff --git a/source/tanya/container/queue.d b/source/tanya/container/queue.d
index e32fdd4..33144c0 100644
--- a/source/tanya/container/queue.d
+++ b/source/tanya/container/queue.d
@@ -14,9 +14,9 @@
  */
 module tanya.container.queue;
 
-import core.exception;
 import std.algorithm.mutation;
 import tanya.container.entry;
+import tanya.exception;
 import tanya.memory;
 import tanya.meta.trait;
 
diff --git a/source/tanya/container/string.d b/source/tanya/container/string.d
index 4b2732b..813fe8a 100644
--- a/source/tanya/container/string.d
+++ b/source/tanya/container/string.d
@@ -361,14 +361,14 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("\u10437"w);
         assert(s == "\u10437");
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Отказаться от вина - в этом страшная вина."d);
         assert(s == "Отказаться от вина - в этом страшная вина.");
@@ -392,8 +392,7 @@ struct String
      *
      * Precondition: $(D_INLINECODE allocator is null).
      */
-    this(S)(S init, shared Allocator allocator = defaultAllocator)
-    nothrow @trusted @nogc
+    this(S)(S init, shared Allocator allocator = defaultAllocator) @trusted
     if (is(S == String))
     {
         this(allocator);
@@ -417,8 +416,7 @@ struct String
     }
 
     /// ditto
-    this(S)(ref S init, shared Allocator allocator = defaultAllocator)
-    nothrow @trusted @nogc
+    this(S)(ref S init, shared Allocator allocator = defaultAllocator) @trusted
     if (is(Unqual!S == String))
     {
         this(allocator);
@@ -428,7 +426,7 @@ struct String
     }
 
     /// ditto
-    this(shared Allocator allocator) pure nothrow @safe @nogc
+    this(shared Allocator allocator) @nogc nothrow pure @safe
     in
     {
         assert(allocator !is null);
@@ -478,7 +476,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         {
             auto s = String(1, 'О');
@@ -494,13 +492,13 @@ struct String
         }
     }
 
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String(0, 'K');
         assert(s.length == 0);
     }
 
-    this(this) @nogc nothrow @trusted
+    this(this) @nogc nothrow pure @trusted
     {
         auto buf = this.data[0 .. this.length_];
         this.length_ = capacity_ = 0;
@@ -511,13 +509,13 @@ struct String
     /**
      * Destroys the string.
      */
-    ~this() nothrow @trusted @nogc
+    ~this() @nogc nothrow pure @trusted
     {
         allocator.resize(this.data[0 .. this.capacity_], 0);
     }
 
     private void write4Bytes(ref const dchar src)
-    pure nothrow @trusted @nogc
+    @nogc nothrow pure @trusted
     in
     {
         assert(capacity - length >= 4);
@@ -578,7 +576,7 @@ struct String
      *
      * Throws: $(D_PSYMBOL UTFException).
      */
-    size_t insertBack(const char chr) @trusted @nogc
+    size_t insertBack(const char chr) @nogc pure @trusted
     {
         if ((chr & 0x80) != 0)
         {
@@ -593,7 +591,7 @@ struct String
     }
 
     /// ditto
-    size_t insertBack(const wchar chr) @trusted @nogc
+    size_t insertBack(const wchar chr) @nogc pure @trusted
     {
         reserve(length + 3);
 
@@ -606,13 +604,13 @@ struct String
     }
 
     // Allocates enough space for 3-byte character.
-    private @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         String s;
         s.insertBack('\u8100');
     }
 
-    private @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         UTFException exception;
         try
@@ -628,7 +626,7 @@ struct String
     }
 
     /// ditto
-    size_t insertBack(const dchar chr) @trusted @nogc
+    size_t insertBack(const dchar chr) @nogc pure @trusted
     {
         reserve(length + dchar.sizeof);
 
@@ -648,7 +646,7 @@ struct String
         }
     }
 
-    private @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         UTFException exception;
         try
@@ -835,7 +833,7 @@ struct String
      * Params:
      *  size = Desired size in bytes.
      */
-    void reserve(const size_t size) nothrow @trusted @nogc
+    void reserve(const size_t size) @nogc nothrow pure @trusted
     {
         if (this.capacity_ >= size)
         {
@@ -847,7 +845,7 @@ struct String
     }
 
     ///
-    @nogc @safe unittest
+    @nogc pure @safe unittest
     {
         String s;
         assert(s.capacity == 0);
@@ -871,7 +869,7 @@ struct String
      * Params:
      *  size = Desired size.
      */
-    void shrink(const size_t size) nothrow @trusted @nogc
+    void shrink(const size_t size) @nogc nothrow pure @trusted
     {
         if (this.capacity_ <= size)
         {
@@ -888,7 +886,7 @@ struct String
     }
 
     ///
-    @nogc @safe unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Die Alten lasen laut.");
         assert(s.capacity == 21);
@@ -907,13 +905,13 @@ struct String
     /**
      * Returns: String capacity in bytes.
      */
-    @property size_t capacity() const pure nothrow @safe @nogc
+    @property size_t capacity() const @nogc nothrow pure @safe
     {
         return this.capacity_;
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("In allem Schreiben ist Schamlosigkeit.");
         assert(s.capacity == 38);
@@ -935,7 +933,7 @@ struct String
      */
     ByCodeUnit!char opSliceAssign(R)(ByCodeUnit!R value,
                                      const size_t i,
-                                     const size_t j) @trusted
+                                     const size_t j)
     if (is(Unqual!R == char))
     in
     {
@@ -954,7 +952,7 @@ struct String
     ByCodeUnit!char opSliceAssign(const char[] value,
                                   const size_t i,
                                   const size_t j)
-    pure nothrow @trusted @nogc
+    @nogc nothrow pure @trusted
     in
     {
         assert(i <= j);
@@ -970,7 +968,7 @@ struct String
     ByCodeUnit!char opSliceAssign(const char value,
                                   const size_t i,
                                   const size_t j)
-    pure nothrow @trusted @nogc
+    @nogc nothrow pure @trusted
     in
     {
         assert(i <= j);
@@ -992,13 +990,13 @@ struct String
      *
      * Returns: The array representing the string.
      */
-    inout(char)[] get() inout pure nothrow @trusted @nogc
+    inout(char)[] get() inout @nogc nothrow pure @trusted
     {
         return this.data[0 .. this.length_];
     }
 
     ///
-    nothrow @safe @nogc unittest
+    @nogc nothrow pure @safe unittest
     {
         auto s = String("Char array.");
         assert(s.get().length == 11);
@@ -1010,7 +1008,7 @@ struct String
      *
      * Returns: Null-terminated string.
      */
-    const(char)* toStringz() nothrow @nogc
+    const(char)* toStringz() @nogc nothrow pure
     {
         reserve(length + 1);
         this.data[length] = '\0';
@@ -1018,7 +1016,7 @@ struct String
     }
 
     ///
-    @nogc unittest
+    @nogc pure unittest
     {
         auto s = String("C string.");
         assert(s.toStringz()[0] == 'C');
@@ -1028,7 +1026,7 @@ struct String
     /**
      * Returns: The number of code units that are required to encode the string.
      */
-    @property size_t length() const pure nothrow @safe @nogc
+    @property size_t length() const @nogc nothrow pure @safe
     {
         return this.length_;
     }
@@ -1037,7 +1035,7 @@ struct String
     alias opDollar = length;
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Piscis primuin a capite foetat.");
         assert(s.length == 31);
@@ -1052,7 +1050,7 @@ struct String
      *
      * Precondition: $(D_INLINECODE length > pos).
      */
-    ref inout(char) opIndex(const size_t pos) inout pure nothrow @trusted @nogc
+    ref inout(char) opIndex(const size_t pos) inout @nogc nothrow pure @trusted
     in
     {
         assert(length > pos);
@@ -1063,7 +1061,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Alea iacta est.");
         assert(s[0] == 'A');
@@ -1074,7 +1072,7 @@ struct String
      * Returns: Random access range that iterates over the string by bytes, in
      *          forward order.
      */
-    ByCodeUnit!char opIndex() pure nothrow @trusted @nogc
+    ByCodeUnit!char opIndex() @nogc nothrow pure @trusted
     {
         return typeof(return)(this, this.data, this.data + length);
     }
@@ -1086,7 +1084,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Plutarchus");
         auto r = s[];
@@ -1104,22 +1102,35 @@ struct String
         assert(r.length == 8);
     }
 
+    ///
+    @nogc pure @safe unittest
+    {
+        auto s = const String("Was ich vermag, soll gern geschehen. Goethe");
+        auto r1 = s[];
+        assert(r1.front == 'W');
+
+        auto r2 = r1[];
+        r1.popFront();
+        assert(r1.front == 'a');
+        assert(r2.front == 'W');
+    }
+
     /**
      * Returns: Forward range that iterates over the string by code points.
      */
-    ByCodePoint!char byCodePoint() pure nothrow @trusted @nogc
+    ByCodePoint!char byCodePoint() @nogc nothrow pure @trusted
     {
         return typeof(return)(this, this.data, this.data + length);
     }
 
     /// ditto
-    ByCodePoint!(const char) byCodePoint() const pure nothrow @trusted @nogc
+    ByCodePoint!(const char) byCodePoint() const @nogc nothrow pure @trusted
     {
         return typeof(return)(this, this.data, this.data + length);
     }
 
     ///
-    @nogc @safe unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Мне есть, что спеть, представ перед Всевышним.");
         auto cp = s.byCodePoint();
@@ -1139,7 +1150,7 @@ struct String
     }
 
     ///
-    @nogc @safe unittest
+    @nogc pure @safe unittest
     {
         auto s = const String("Высоцкий");
         auto cp1 = s.byCodePoint();
@@ -1157,15 +1168,18 @@ struct String
     }
 
     /**
-     * Returns: $(D_KEYWORD true) if the string is empty.
+     * Returns whether the string is empty.
+     *
+     * Returns: $(D_KEYWORD true) if the string is empty, $(D_KEYWORD false)
+     *          otherwise.
      */
-    @property bool empty() const pure nothrow @safe @nogc
+    @property bool empty() const @nogc nothrow pure @safe
     {
         return length == 0;
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         String s;
         assert(s.empty);
@@ -1185,7 +1199,7 @@ struct String
      * Precondition: $(D_INLINECODE i <= j && j <= length).
      */
     ByCodeUnit!char opSlice(const size_t i, const size_t j)
-    pure nothrow @trusted @nogc
+    @nogc nothrow pure @trusted
     in
     {
         assert(i <= j);
@@ -1198,7 +1212,7 @@ struct String
 
     /// ditto
     ByCodeUnit!(const char) opSlice(const size_t i, const size_t j)
-    const pure nothrow @trusted @nogc
+    const @nogc nothrow pure @trusted
     in
     {
         assert(i <= j);
@@ -1210,7 +1224,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Vladimir Soloviev");
         auto r = s[9 .. $];
@@ -1274,7 +1288,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Черная, потом пропахшая выть!");
         s = String("Как мне тебя не ласкать, не любить?");
@@ -1291,7 +1305,7 @@ struct String
      *
      * Throws: $(D_PSYMBOL UTFException).
      */
-    ref String opAssign(S)(S that) nothrow
+    ref String opAssign(S)(S that)
     if (!isInfinite!S
      && isInputRange!S
      && isSomeChar!(ElementType!S))
@@ -1302,7 +1316,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Оловом светится лужная голь...");
         s = "Грустная песня, ты - русская боль.";
@@ -1347,7 +1361,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         assert(String("Голубая кофта.") < String("Синие глаза."));
         assert(String("Никакой я правды") < String("милой не сказал")[]);
@@ -1400,7 +1414,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         assert(String("Милая спросила:") != String("Крутит ли метель?"));
         assert(String("Затопить бы печку,") != String("постелить постель.")[]);
@@ -1427,13 +1441,13 @@ struct String
      * Precondition: $(D_INLINECODE length > pos).
      */
     ref char opIndexAssign(const char value, const size_t pos)
-    pure nothrow @safe @nogc
+    @nogc nothrow pure @safe
     {
         return opIndex(pos) = value;
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("alea iacta est.");
 
@@ -1458,7 +1472,7 @@ struct String
         return opSliceAssign(value, 0, length);
     }
 
-    private unittest
+    @nogc pure @safe unittest
     {
         auto s1 = String("Buttercup");
         auto s2 = String("Cap");
@@ -1467,12 +1481,12 @@ struct String
     }
 
     /// ditto
-    ByCodeUnit!char opIndexAssign(const char value) pure nothrow @safe @nogc
+    ByCodeUnit!char opIndexAssign(const char value) @nogc nothrow pure @safe
     {
         return opSliceAssign(value, 0, length);
     }
 
-    private unittest
+    @nogc pure @safe unittest
     {
         auto s1 = String("Wow");
         s1[] = 'a';
@@ -1480,12 +1494,12 @@ struct String
     }
 
     /// ditto
-    ByCodeUnit!char opIndexAssign(const char[] value) pure nothrow @safe @nogc
+    ByCodeUnit!char opIndexAssign(const char[] value) @nogc nothrow pure @safe
     {
         return opSliceAssign(value, 0, length);
     }
 
-    private unittest
+    @nogc pure @safe unittest
     {
         auto s1 = String("ö");
         s1[] = "oe";
@@ -1521,7 +1535,7 @@ struct String
     }
 
     ///
-    @nogc @safe unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Из пословицы слова не выкинешь.");
 
@@ -1575,7 +1589,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Казнить нельзя помиловать.");
         s.insertAfter(s[0 .. 27], ",");
@@ -1604,7 +1618,7 @@ struct String
     }
 
     ///
-    @safe @nogc unittest
+    @nogc pure @safe unittest
     {
         auto s = String("Казнить нельзя помиловать.");
         s.insertBefore(s[27 .. $], ",");
@@ -1619,7 +1633,7 @@ struct String
 }
 
 // Postblit works.
-@nogc @safe unittest
+@nogc pure @safe unittest
 {
     void internFunc(String arg)
     {
diff --git a/source/tanya/conv.d b/source/tanya/conv.d
new file mode 100644
index 0000000..5a5fac6
--- /dev/null
+++ b/source/tanya/conv.d
@@ -0,0 +1,235 @@
+/* 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/. */
+
+/**
+ * This module provides functions for converting between different types.
+ *
+ * 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/conv.d,
+ *                 tanya/conv.d)
+ */
+module tanya.conv;
+
+import tanya.memory;
+import tanya.memory.op;
+import tanya.meta.trait;
+
+/**
+ * Constructs a new object of type $(D_PARAM T) in $(D_PARAM memory) with the
+ * given arguments.
+ *
+ * If $(D_PARAM T) is a $(D_KEYWORD class), emplace returns a class reference
+ * of type $(D_PARAM T), otherwise a pointer to the constructed object is
+ * returned.
+ *
+ * If $(D_PARAM T) is a nested class inside another class, $(D_PARAM outer)
+ * should be an instance of the outer class.
+ *
+ * $(D_PARAM args) are arguments for the constructor of $(D_PARAM T). If
+ * $(D_PARAM T) isn't an aggregate type and doesn't have a constructor,
+ * $(D_PARAM memory) can be initialized to `args[0]` if `Args.length == 1`,
+ * `Args[0]` should be implicitly convertible to $(D_PARAM T) then.
+ *
+ * Params:
+ *  T     = Constructed type.
+ *  U     = Type of the outer class if $(D_PARAM T) is a nested class.
+ *  Args  = Types of the constructor arguments if $(D_PARAM T) has a constructor
+ *          or the type of the initial value.
+ *  outer = Outer class instance if $(D_PARAM T) is a nested class.
+ *  args  = Constructor arguments if $(D_PARAM T) has a constructor or the
+ *          initial value.
+ *
+ * Returns: New instance of type $(D_PARAM T) constructed in $(D_PARAM memory).
+ *
+ * Precondition: `memory.length == stateSize!T`.
+ * Postcondition: $(D_PARAM memory) and the result point to the same memory.
+ */
+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)());
+}
+body
+{
+    copy(typeid(T).initializer, memory);
+
+    auto result = (() @trusted => cast(T) memory.ptr)();
+    result.outer = outer;
+
+    static if (is(typeof(result.__ctor(args))))
+    {
+        result.__ctor(args);
+    }
+
+    return result;
+}
+
+/// 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)());
+}body
+{
+    copy(typeid(T).initializer, memory);
+
+    auto result = (() @trusted => cast(T) memory.ptr)();
+    static if (is(typeof(result.__ctor(args))))
+    {
+        result.__ctor(args);
+    }
+    return result;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    import tanya.memory : stateSize;
+
+    class C
+    {
+        int i = 5;
+        class Inner
+        {
+            int i;
+
+            this(int param) pure nothrow @safe @nogc
+            {
+                this.i = param;
+            }
+        }
+    }
+    ubyte[stateSize!C] memory1;
+    ubyte[stateSize!(C.Inner)] memory2;
+
+    auto c = emplace!C(memory1);
+    assert(c.i == 5);
+
+    auto inner = emplace!(C.Inner)(memory2, c, 8);
+    assert(c.i == 5);
+    assert(inner.i == 8);
+    assert(inner.outer is c);
+}
+
+/// 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);
+}
+body
+{
+    auto result = (() @trusted => cast(T*) memory.ptr)();
+    static if (Args.length == 1)
+    {
+        *result = T(args[0]);
+    }
+    else
+    {
+        *result = T.init;
+    }
+    return result;
+}
+
+/// ditto
+T* emplace(T, Args...)(void[] memory, auto ref Args args)
+if (!isPolymorphicType!T && isAggregateType!T)
+in
+{
+    assert(memory.length >= T.sizeof);
+}
+out (result)
+{
+    assert(memory.ptr is result);
+}
+body
+{
+    auto result = (() @trusted => cast(T*) memory.ptr)();
+    static if (!hasElaborateAssign!T && isAssignable!T)
+    {
+        *result = T.init;
+    }
+    else
+    {
+        static const T init = T.init;
+        copy((cast(void*) &init)[0 .. T.sizeof], memory);
+    }
+
+    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);
+    }
+    else static if (is(typeof(result.__ctor(args))))
+    {
+        result.__ctor(args);
+    }
+    else
+    {
+        static assert(false,
+                      "Unable to construct value with the given arguments");
+    }
+    return result;
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    ubyte[4] memory;
+
+    auto i = emplace!int(memory);
+    static assert(is(typeof(i) == int*));
+    assert(*i == 0);
+
+    i = emplace!int(memory, 5);
+    assert(*i == 5);
+
+    static struct S
+    {
+        int i;
+        @disable this();
+        @disable this(this);
+        this(int i) @nogc nothrow pure @safe
+        {
+            this.i = i;
+        }
+    }
+    auto s = emplace!S(memory, 8);
+    static assert(is(typeof(s) == S*));
+    assert(s.i == 8);
+}
+
+// Handles "Cannot access frame pointer" error.
+@nogc nothrow pure @safe unittest
+{
+    struct F
+    {
+        ~this() @nogc nothrow pure @safe
+        {
+        }
+    }
+    static assert(is(typeof(emplace!F((void[]).init))));
+}
diff --git a/source/tanya/exception.d b/source/tanya/exception.d
new file mode 100644
index 0000000..c329999
--- /dev/null
+++ b/source/tanya/exception.d
@@ -0,0 +1,66 @@
+/* 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/. */
+
+/**
+ * Common exceptions and errors.
+ *
+ * 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/exception.d,
+ *                 tanya/exception.d)
+ */
+module tanya.exception;
+
+import tanya.conv;
+import tanya.memory;
+
+/**
+ * Error thrown if memory allocation fails.
+ */
+final class OutOfMemoryError : Error
+{
+    /**
+     * Constructs new error.
+     *
+     * 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 = "Out of memory",
+         string file = __FILE__,
+         size_t line = __LINE__,
+         Throwable next = null) @nogc nothrow pure @safe
+    {
+        super(msg, file, line, next);
+    }
+
+    /// ditto
+    this(string msg,
+         Throwable next,
+         string file = __FILE__,
+         size_t line = __LINE__) @nogc nothrow pure @safe
+    {
+        super(msg, file, line, next);
+    }
+}
+
+/**
+ * Allocates $(D_PSYMBOL OutOfMemoryError) in a static storage and throws it.
+ *
+ * Params:
+ *  msg = Custom error message.
+ *
+ * Throws: $(D_PSYMBOL OutOfMemoryError).
+ */
+void onOutOfMemoryError(string msg = "Out of memory")
+@nogc nothrow pure @trusted
+{
+    static ubyte[stateSize!OutOfMemoryError] memory;
+    alias PureType = OutOfMemoryError function(string) @nogc nothrow pure;
+    throw (cast(PureType) () => emplace!OutOfMemoryError(memory))(msg);
+}
diff --git a/source/tanya/memory/package.d b/source/tanya/memory/package.d
index e49aaf5..1310f37 100644
--- a/source/tanya/memory/package.d
+++ b/source/tanya/memory/package.d
@@ -14,10 +14,10 @@
  */
 module tanya.memory;
 
-import core.exception;
 import std.algorithm.iteration;
 import std.algorithm.mutation;
-import std.conv;
+import tanya.conv;
+import tanya.exception;
 public import tanya.memory.allocator;
 import tanya.memory.mmappool;
 import tanya.meta.trait;
@@ -229,14 +229,14 @@ package(tanya) T[] resize(T)(shared Allocator allocator,
         }
         else
         {
-            onOutOfMemoryErrorNoGC();
+            onOutOfMemoryError();
         }
     }
 
     void[] buf = array;
     if (!allocator.reallocate(buf, length * T.sizeof))
     {
-        onOutOfMemoryErrorNoGC();
+        onOutOfMemoryError();
     }
     // Casting from void[] is unsafe, but we know we cast to the original type.
     array = cast(T[]) buf;
@@ -453,9 +453,7 @@ body
     {
         () @trusted { allocator.deallocate(mem); }();
     }
-
-    auto ptr = (() @trusted => (cast(T*) mem[0 .. stateSize!T].ptr))();
-    return emplace!T(ptr, args);
+    return emplace!T(mem[0 .. stateSize!T], args);
 }
 
 ///
diff --git a/source/tanya/memory/smartref.d b/source/tanya/memory/smartref.d
index f142513..bc7999f 100644
--- a/source/tanya/memory/smartref.d
+++ b/source/tanya/memory/smartref.d
@@ -6,7 +6,13 @@
  * Smart pointers.
  *
  * A smart pointer is an object that wraps a raw pointer or a reference
- * (class, array) to manage its lifetime.
+ * (class, dynamic array) to manage its lifetime.
+ *
+ * This module provides two kinds of lifetime management strategies:
+ * $(UL
+ *  $(LI Reference counting)
+ *  $(LI Unique ownership)
+ * )
  *
  * Copyright: Eugene Wissner 2016-2017.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
@@ -17,17 +23,17 @@
  */
 module tanya.memory.smartref;
 
-import core.exception;
 import std.algorithm.comparison;
 import std.algorithm.mutation;
-import std.conv;
+import tanya.conv;
+import tanya.exception;
 import tanya.memory;
 import tanya.meta.trait;
 import tanya.range.primitive;
 
 private template Payload(T)
 {
-    static if (is(T == class) || is(T == interface) || isArray!T)
+    static if (isPolymorphicType!T || isArray!T)
     {
         alias Payload = T;
     }
@@ -202,13 +208,6 @@ struct RefCounted(T)
         return this;
     }
 
-    private @nogc unittest
-    {
-        auto rc = defaultAllocator.refCounted!int(5);
-        rc = defaultAllocator.make!int(7);
-        assert(*rc == 7);
-    }
-
     /// ditto
     ref typeof(this) opAssign(typeof(null))
     {
@@ -229,14 +228,6 @@ struct RefCounted(T)
         return this;
     }
 
-    private @nogc unittest
-    {
-        RefCounted!int rc;
-        assert(!rc.isInitialized);
-        rc = null;
-        assert(!rc.isInitialized);
-    }
-
     /// ditto
     ref typeof(this) opAssign(typeof(this) rhs)
     {
@@ -308,7 +299,7 @@ struct RefCounted(T)
 }
 
 ///
-unittest
+@nogc @system unittest
 {
     auto rc = RefCounted!int(defaultAllocator.make!int(5), defaultAllocator);
     auto val = rc.get();
@@ -324,7 +315,22 @@ unittest
     assert(*rc.storage.payload == 9);
 }
 
-private @nogc unittest
+@nogc @system unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    rc = defaultAllocator.make!int(7);
+    assert(*rc == 7);
+}
+
+@nogc @system unittest
+{
+    RefCounted!int rc;
+    assert(!rc.isInitialized);
+    rc = null;
+    assert(!rc.isInitialized);
+}
+
+@nogc @system unittest
 {
     auto rc = defaultAllocator.refCounted!int(5);
 
@@ -340,7 +346,7 @@ private @nogc unittest
     assert(*rc == 5);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     RefCounted!int rc;
 
@@ -355,7 +361,7 @@ private @nogc unittest
     assert(rc.count == 0);
 }
 
-private unittest
+@nogc @system unittest
 {
     RefCounted!int rc1, rc2;
     static assert(is(typeof(rc1 = rc2)));
@@ -389,7 +395,7 @@ version (unittest)
     }
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     uint destroyed;
     auto a = defaultAllocator.make!A(destroyed);
@@ -399,7 +405,7 @@ private @nogc unittest
         auto rc = RefCounted!A(a, defaultAllocator);
         assert(rc.count == 1);
 
-        void func(RefCounted!A rc) @nogc
+        void func(RefCounted!A rc) @nogc @system
         {
             assert(rc.count == 2);
         }
@@ -415,14 +421,14 @@ private @nogc unittest
     assert(rc.count == 1);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     auto rc = RefCounted!int(defaultAllocator);
     assert(!rc.isInitialized);
     assert(rc.allocator is defaultAllocator);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     auto rc = defaultAllocator.refCounted!int(5);
     assert(rc.count == 1);
@@ -444,7 +450,7 @@ private @nogc unittest
     assert(rc.count == 0);
 }
 
-private unittest
+@nogc @system unittest
 {
     auto rc = defaultAllocator.refCounted!int(5);
     assert(*rc == 5);
@@ -460,7 +466,7 @@ private unittest
     assert(*rc == 5);
 }
 
-private unittest
+@nogc nothrow pure @safe unittest
 {
     static assert(is(typeof(RefCounted!int.storage.payload) == int*));
     static assert(is(typeof(RefCounted!A.storage.payload) == A));
@@ -511,17 +517,9 @@ body
     {
         () @trusted { allocator.deallocate(mem); }();
     }
-    rc.storage = emplace!((RefCounted!T.Storage))(mem[0 .. storageSize]);
+    rc.storage = emplace!(RefCounted!T.Storage)(mem[0 .. storageSize]);
+    rc.storage.payload = emplace!T(mem[storageSize .. $], args);
 
-    static if (is(T == class))
-    {
-        rc.storage.payload = emplace!T(mem[storageSize .. $], args);
-    }
-    else
-    {
-        auto ptr = (() @trusted => (cast(T*) mem[storageSize .. $].ptr))();
-        rc.storage.payload = emplace!T(ptr, args);
-    }
     rc.deleter = &unifiedDeleter!(Payload!T);
     return rc;
 }
@@ -554,7 +552,7 @@ body
 }
 
 ///
-unittest
+@nogc @system unittest
 {
     auto rc = defaultAllocator.refCounted!int(5);
     assert(rc.count == 1);
@@ -575,7 +573,7 @@ unittest
     assert(rc.count == 1);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     struct E
     {
@@ -597,13 +595,13 @@ private @nogc unittest
     }
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     auto rc = defaultAllocator.refCounted!(int[])(5);
     assert(rc.length == 5);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     auto p1 = defaultAllocator.make!int(5);
     auto p2 = p1;
@@ -611,13 +609,13 @@ private @nogc unittest
     assert(rc.get() is p2);
 }
 
-private @nogc unittest
+@nogc @system unittest
 {
     static bool destroyed = false;
 
-    struct F
+    static struct F
     {
-        ~this() @nogc
+        ~this() @nogc nothrow @safe
         {
             destroyed = true;
         }
@@ -723,7 +721,7 @@ struct Unique(T)
     }
 
     ///
-    @nogc unittest
+    @nogc nothrow pure @system unittest
     {
         auto rc = defaultAllocator.unique!int(5);
         rc = defaultAllocator.make!int(7);
@@ -770,7 +768,7 @@ struct Unique(T)
     }
 
     ///
-    @nogc unittest
+    @nogc nothrow pure @system unittest
     {
         Unique!int u;
         assert(!u.isInitialized);
@@ -789,7 +787,7 @@ struct Unique(T)
     }
 
     ///
-    @nogc unittest
+    @nogc nothrow pure @system unittest
     {
         auto u = defaultAllocator.unique!int(5);
         assert(u.isInitialized);
@@ -804,7 +802,7 @@ struct Unique(T)
 }
 
 ///
-@nogc unittest
+@nogc nothrow pure @system unittest
 {
     auto p = defaultAllocator.make!int(5);
     auto s = Unique!int(p, defaultAllocator);
@@ -812,13 +810,13 @@ struct Unique(T)
 }
 
 ///
-@nogc unittest
+@nogc nothrow @system unittest
 {
     static bool destroyed = false;
 
-    struct F
+    static struct F
     {
-        ~this() @nogc
+        ~this() @nogc nothrow @safe
         {
             destroyed = true;
         }
@@ -885,13 +883,13 @@ body
     return Unique!T(payload, allocator);
 }
 
-private unittest
+@nogc nothrow pure @safe unittest
 {
     static assert(is(typeof(defaultAllocator.unique!B(5))));
     static assert(is(typeof(defaultAllocator.unique!(int[])(5))));
 }
 
-private unittest
+@nogc nothrow pure @system unittest
 {
     auto s = defaultAllocator.unique!int(5);
     assert(*s == 5);
@@ -900,7 +898,7 @@ private unittest
     assert(s is null);
 }
 
-private unittest
+@nogc nothrow pure @system unittest
 {
     auto s = defaultAllocator.unique!int(5);
     assert(*s == 5);
@@ -909,7 +907,7 @@ private unittest
     assert(*s == 4);
 }
 
-private @nogc unittest
+@nogc nothrow pure @system unittest
 {
     auto p1 = defaultAllocator.make!int(5);
     auto p2 = p1;
@@ -918,7 +916,7 @@ private @nogc unittest
     assert(rc.get() is p2);
 }
 
-private @nogc unittest
+@nogc nothrow pure @system unittest
 {
     auto rc = Unique!int(defaultAllocator);
     assert(rc.allocator is defaultAllocator);