Make Unique.get and RefCounted.get return inout

Also revert the renaming of Scoped to Unique. And rename the whole
module to memory.smartref.

source/tanya/memory/smartref.d

@@ -0,0 +1,847 @@
+/* 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/. */
+
+/**
+ * Smart pointers.
+ *
+ * Copyright: Eugene Wissner 2016-2017.
+ * 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)
+ */
+module tanya.memory.smartref;
+
+import core.exception;
+import std.algorithm.comparison;
+import std.algorithm.mutation;
+import std.conv;
+import std.range;
+import std.traits;
+import tanya.memory;
+
+package template Payload(T)
+{
+    static if (is(T == class) || is(T == interface) || isArray!T)
+    {
+        alias Payload = T;
+    }
+    else
+    {
+        alias Payload = T*;
+    }
+}
+
+package final class RefCountedStore(T)
+{
+    T payload;
+    size_t counter = 1;
+
+    size_t opUnary(string op)()
+        if (op == "--" || op == "++")
+    in
+    {
+        assert(counter > 0);
+    }
+    body
+    {
+        mixin("return " ~ op ~ "counter;");
+    }
+
+    int opCmp(const size_t counter)
+    {
+        if (this.counter > counter)
+        {
+            return 1;
+        }
+        else if (this.counter < counter)
+        {
+            return -1;
+        }
+        else
+        {
+            return 0;
+        }
+    }
+
+    int opEquals(const size_t counter)
+    {
+        return this.counter == counter;
+    }
+}
+
+package void separateDeleter(T)(RefCountedStore!T storage,
+                                shared Allocator allocator)
+{
+    allocator.dispose(storage.payload);
+    allocator.dispose(storage);
+}
+
+package void unifiedDeleter(T)(RefCountedStore!T storage,
+                               shared Allocator allocator)
+{
+    auto ptr1 = finalize(storage);
+    auto ptr2 = finalize(storage.payload);
+    allocator.deallocate(ptr1.ptr[0 .. ptr1.length + ptr2.length]);
+}
+
+/**
+ * Reference-counted object containing a $(D_PARAM T) value as payload.
+ * $(D_PSYMBOL RefCounted) keeps track of all references of an object, and
+ * when the reference count goes down to zero, frees the underlying store.
+ *
+ * Params:
+ *  T = Type of the reference-counted value.
+ */
+struct RefCounted(T)
+{
+    private alias Storage = RefCountedStore!(Payload!T);
+
+    private Storage storage;
+    private void function(Storage storage,
+                          shared Allocator allocator) @nogc deleter;
+
+    invariant
+    {
+        assert(storage is null || allocator_ !is null);
+        assert(storage is null || deleter !is null);
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM value), setting the counter to 1.
+     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
+     *
+     * Params:
+     *  value     = Value whose ownership is taken over.
+     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
+     *              allocate/deallocate internal storage.
+     *
+     * Precondition: $(D_INLINECODE allocator !is null)
+     */
+    this()(auto ref Payload!T value,
+           shared Allocator allocator = defaultAllocator)
+    {
+        this(allocator);
+        this.storage = allocator.make!Storage();
+        this.deleter = &separateDeleter!(Payload!T);
+
+        move(value, this.storage.payload);
+        static if (__traits(isRef, value))
+        {
+            value = null;
+        }
+    }
+
+    /// Ditto.
+    this(shared Allocator allocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.allocator_ = allocator;
+    }
+
+    /**
+     * Increases the reference counter by one.
+     */
+    this(this)
+    {
+        if (count != 0)
+        {
+            ++this.storage;
+        }
+    }
+
+    /**
+     * Decreases the reference counter by one.
+     *
+     * If the counter reaches 0, destroys the owned object.
+     */
+    ~this()
+    {
+        if (this.storage !is null && !(this.storage.counter && --this.storage))
+        {
+            deleter(this.storage, allocator);
+        }
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM rhs). Initializes this
+     * $(D_PSYMBOL RefCounted) if needed.
+     *
+     * If it is the last reference of the previously owned object,
+     * it will be destroyed.
+     *
+     * To reset $(D_PSYMBOL RefCounted) assign $(D_KEYWORD null).
+     *
+     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
+     * be used. If you need a different allocator, create a new
+     * $(D_PSYMBOL RefCounted) and assign it.
+     *
+     * Params:
+     *  rhs = New object.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign()(auto ref Payload!T rhs)
+    {
+        if (this.storage is null)
+        {
+            this.storage = allocator.make!Storage();
+            this.deleter = &separateDeleter!(Payload!T);
+        }
+        else if (this.storage > 1)
+        {
+            --this.storage;
+            this.storage = allocator.make!Storage();
+            this.deleter = &separateDeleter!(Payload!T);
+        }
+        else
+        {
+            finalize(this.storage.payload);
+            this.storage.payload = Payload!T.init;
+        }
+        move(rhs, this.storage.payload);
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(null))
+    {
+        if (this.storage is null)
+        {
+            return this;
+        }
+        else if (this.storage > 1)
+        {
+            --this.storage;
+        }
+        else
+        {
+            deleter(this.storage, allocator);
+        }
+        this.storage = null;
+
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(this) rhs)
+    {
+        swap(this.allocator_, rhs.allocator_);
+        swap(this.storage, rhs.storage);
+        swap(this.deleter, rhs.deleter);
+        return this;
+    }
+
+    /**
+     * Returns: Reference to the owned object.
+     *
+     * Precondition: $(D_INLINECODE cound > 0).
+     */
+    inout(Payload!T) get() inout pure nothrow @safe @nogc
+    in
+    {
+        assert(count > 0, "Attempted to access an uninitialized reference.");
+    }
+    body
+    {
+        return storage.payload;
+    }
+
+    version (D_Ddoc)
+    {
+        /**
+         * Params:
+         *  op = Operation. 
+         *
+         * Dereferences the pointer. It is defined only for pointers, not for
+         * reference types like classes, that can be accessed directly.
+         *
+         * Returns: Reference to the pointed value.
+         */
+        ref inout(T) opUnary(string op)() inout
+            if (op == "*");
+    }
+    else static if (isPointer!(Payload!T))
+    {
+        ref inout(T) opUnary(string op)() inout
+            if (op == "*")
+        {
+            return *storage.payload;
+        }
+    }
+
+    /**
+     * Returns: Whether this $(D_PSYMBOL RefCounted) already has an internal 
+     *          storage.
+     */
+    @property bool isInitialized() const
+    {
+        return storage !is null;
+    }
+
+    /**
+     * Returns: The number of $(D_PSYMBOL RefCounted) instances that share
+     *          ownership over the same pointer (including $(D_KEYWORD this)).
+     *          If this $(D_PSYMBOL RefCounted) isn't initialized, returns `0`.
+     */
+    @property size_t count() const
+    {
+        return storage is null ? 0 : storage.counter;
+    }
+
+    mixin DefaultAllocator;
+    alias get this;
+}
+
+///
+unittest
+{
+    auto rc = RefCounted!int(defaultAllocator.make!int(5), defaultAllocator);
+    auto val = rc.get();
+
+    *val = 8;
+    assert(*rc.storage.payload == 8);
+
+    val = null;
+    assert(rc.storage.payload !is null);
+    assert(*rc.storage.payload == 8);
+
+    *rc = 9;
+    assert(*rc.storage.payload == 9);
+}
+
+version (unittest)
+{
+    private class A
+    {
+        uint *destroyed;
+
+        this(ref uint destroyed) @nogc
+        {
+            this.destroyed = &destroyed;
+        }
+
+        ~this() @nogc
+        {
+            ++(*destroyed);
+        }
+    }
+
+    private struct B
+    {
+        int prop;
+        @disable this();
+        this(int param1) @nogc
+        {
+            prop = param1;
+        }
+    }
+}
+
+private @nogc unittest
+{
+    uint destroyed;
+    auto a = defaultAllocator.make!A(destroyed);
+
+    assert(destroyed == 0);
+    {
+        auto rc = RefCounted!A(a, defaultAllocator);
+        assert(rc.count == 1);
+
+        void func(RefCounted!A rc) @nogc
+        {
+            assert(rc.count == 2);
+        }
+        func(rc);
+
+        assert(rc.count == 1);
+    }
+    assert(destroyed == 1);
+
+    RefCounted!int rc;
+    assert(rc.count == 0);
+    rc = defaultAllocator.make!int(8);
+    assert(rc.count == 1);
+}
+
+private @nogc unittest
+{
+    auto rc = RefCounted!int(defaultAllocator);
+    assert(!rc.isInitialized);
+    assert(rc.allocator is defaultAllocator);
+}
+
+private @nogc unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(rc.count == 1);
+
+    void func(RefCounted!int rc) @nogc
+    {
+        assert(rc.count == 2);
+        rc = null;
+        assert(!rc.isInitialized);
+        assert(rc.count == 0);
+    }
+
+    assert(rc.count == 1);
+    func(rc);
+    assert(rc.count == 1);
+
+    rc = null;
+    assert(!rc.isInitialized);
+    assert(rc.count == 0);
+}
+
+private unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(*rc == 5);
+
+    void func(RefCounted!int rc) @nogc
+    {
+        assert(rc.count == 2);
+        rc = defaultAllocator.refCounted!int(4);
+        assert(*rc == 4);
+        assert(rc.count == 1);
+    }
+    func(rc);
+    assert(*rc == 5);
+}
+
+private unittest
+{
+    static assert(is(typeof(RefCounted!int.storage.payload) == int*));
+    static assert(is(typeof(RefCounted!A.storage.payload) == A));
+
+    static assert(is(RefCounted!B));
+    static assert(is(RefCounted!A));
+}
+
+/**
+ * Constructs a new object of type $(D_PARAM T) and wraps it in a
+ * $(D_PSYMBOL RefCounted) using $(D_PARAM args) as the parameter list for
+ * the constructor of $(D_PARAM T).
+ *
+ * This function is more efficient than the using of $(D_PSYMBOL RefCounted)
+ * directly, since it allocates only ones (the internal storage and the
+ * object).
+ *
+ * Params:
+ *  T         = Type of the constructed object.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Newly created $(D_PSYMBOL RefCounted!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+RefCounted!T refCounted(T, A...)(shared Allocator allocator, auto ref A args)
+    if (!is(T == interface) && !isAbstractClass!T
+     && !isAssociativeArray!T && !isArray!T)
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    auto rc = typeof(return)(allocator);
+
+    const storageSize = alignedSize(stateSize!(RefCounted!T.Storage));
+    const size = alignedSize(stateSize!T + storageSize);
+
+    auto mem = (() @trusted => allocator.allocate(size))();
+    if (mem is null)
+    {
+        onOutOfMemoryError();
+    }
+    scope (failure)
+    {
+        () @trusted { allocator.deallocate(mem); }();
+    }
+    rc.storage = emplace!((RefCounted!T.Storage))(mem[0 .. storageSize]);
+
+    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;
+}
+
+/**
+ * Constructs a new array with $(D_PARAM size) elements and wraps it in a
+ * $(D_PSYMBOL RefCounted).
+ *
+ * Params:
+ *  T         = Array type.
+ *  size      = Array size.
+ *  allocator = Allocator.
+ *
+ * Returns: Newly created $(D_PSYMBOL RefCounted!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null
+ *                           && size <= size_t.max / ElementType!T.sizeof)
+ */
+RefCounted!T refCounted(T)(shared Allocator allocator, const size_t size)
+@trusted
+    if (isArray!T)
+in
+{
+    assert(allocator !is null);
+    assert(size <= size_t.max / ElementType!T.sizeof);
+}
+body
+{
+    auto payload = allocator.resize!(ElementType!T)(null, size);
+    return RefCounted!T(payload, allocator);
+}
+
+///
+unittest
+{
+    auto rc = defaultAllocator.refCounted!int(5);
+    assert(rc.count == 1);
+
+    void func(RefCounted!int param) @nogc
+    {
+        if (param.count == 2)
+        {
+            func(param);
+        }
+        else
+        {
+            assert(param.count == 3);
+        }
+    }
+    func(rc);
+
+    assert(rc.count == 1);
+}
+
+private @nogc unittest
+{
+    struct E
+    {
+    }
+    auto b = defaultAllocator.refCounted!B(15);
+    static assert(is(typeof(b.storage.payload) == B*));
+    static assert(is(typeof(b.prop) == int));
+    static assert(!is(typeof(defaultAllocator.refCounted!B())));
+
+    static assert(is(typeof(defaultAllocator.refCounted!E())));
+    static assert(!is(typeof(defaultAllocator.refCounted!E(5))));
+    {
+        auto rc = defaultAllocator.refCounted!B(3);
+        assert(rc.get().prop == 3);
+    }
+    {
+        auto rc = defaultAllocator.refCounted!E();
+        assert(rc.count);
+    }
+}
+
+private @nogc unittest
+{
+    auto rc = defaultAllocator.refCounted!(int[])(5);
+    assert(rc.length == 5);
+}
+
+private @nogc unittest
+{
+    auto p1 = defaultAllocator.make!int(5);
+    auto p2 = p1;
+    auto rc = RefCounted!int(p1, defaultAllocator);
+
+    assert(p1 is null);
+    assert(rc.get() is p2);
+}
+
+private @nogc unittest
+{
+    static bool destroyed = false;
+
+    struct F
+    {
+        ~this() @nogc
+        {
+            destroyed = true;
+        }
+    }
+    {
+        auto rc = defaultAllocator.refCounted!F();
+    }
+    assert(destroyed);
+}
+
+/**
+ * $(D_PSYMBOL Unique) stores an object that gets destroyed at the end of its scope.
+ *
+ * Params:
+ *  T = Value type.
+ */
+struct Unique(T)
+{
+    private Payload!T payload;
+
+    invariant
+    {
+        assert(payload is null || allocator_ !is null);
+    }
+
+    /**
+     * Takes ownership over $(D_PARAM value), setting the counter to 1.
+     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
+     *
+     * Params:
+     *  value     = Value whose ownership is taken over.
+     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
+     *              allocate/deallocate internal storage.
+     *
+     * Precondition: $(D_INLINECODE allocator !is null)
+     */
+    this()(auto ref Payload!T value,
+           shared Allocator allocator = defaultAllocator)
+    {
+        this(allocator);
+
+        move(value, this.payload);
+        static if (__traits(isRef, value))
+        {
+            value = null;
+        }
+    }
+
+    /// Ditto.
+    this(shared Allocator allocator)
+    in
+    {
+        assert(allocator !is null);
+    }
+    body
+    {
+        this.allocator_ = allocator;
+    }
+
+    /**
+     * $(D_PSYMBOL Unique) is noncopyable.
+     */
+    @disable this(this);
+
+    /**
+     * Destroys the owned object.
+     */
+    ~this()
+    {
+        if (this.payload !is null)
+        {
+            allocator.dispose(this.payload);
+        }
+    }
+
+    /**
+     * Initialized this $(D_PARAM Unique) and takes ownership over
+     * $(D_PARAM rhs).
+     *
+     * To reset $(D_PSYMBOL Unique) assign $(D_KEYWORD null).
+     *
+     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
+     * be used. If you need a different allocator, create a new
+     * $(D_PSYMBOL Unique) and assign it.
+     *
+     * Params:
+     *  rhs = New object.
+     *
+     * Returns: $(D_KEYWORD this).
+     */
+    ref typeof(this) opAssign()(auto ref Payload!T rhs)
+    {
+        allocator.dispose(this.payload);
+        move(rhs, this.payload);
+
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(null))
+    {
+        allocator.dispose(this.payload);
+        return this;
+    }
+
+    /// Ditto.
+    ref typeof(this) opAssign(typeof(this) rhs)
+    {
+        swap(this.allocator_, rhs.allocator_);
+        swap(this.payload, rhs.payload);
+
+        return this;
+    }
+
+    /**
+     * Returns: Reference to the owned object.
+     */
+    inout(Payload!T) get() inout pure nothrow @safe @nogc
+    {
+        return payload;
+    }
+
+    version (D_Ddoc)
+    {
+        /**
+         * Params:
+         *  op = Operation. 
+         *
+         * Dereferences the pointer. It is defined only for pointers, not for
+         * reference types like classes, that can be accessed directly.
+         *
+         * Returns: Reference to the pointed value.
+         */
+        ref inout(T) opUnary(string op)() inout
+            if (op == "*");
+    }
+    else static if (isPointer!(Payload!T))
+    {
+        ref inout(T) opUnary(string op)() inout
+            if (op == "*")
+        {
+            return *payload;
+        }
+    }
+
+    mixin DefaultAllocator;
+    alias get this;
+}
+
+///
+@nogc unittest
+{
+    auto p = defaultAllocator.make!int(5);
+    auto s = Unique!int(p, defaultAllocator);
+    assert(p is null);
+    assert(*s == 5);
+}
+
+///
+@nogc unittest
+{
+    static bool destroyed = false;
+
+    struct F
+    {
+        ~this() @nogc
+        {
+            destroyed = true;
+        }
+    }
+    {
+        auto s = Unique!F(defaultAllocator.make!F(), defaultAllocator);
+    }
+    assert(destroyed);
+}
+
+/**
+ * Constructs a new object of type $(D_PARAM T) and wraps it in a
+ * $(D_PSYMBOL Unique) using $(D_PARAM args) as the parameter list for
+ * the constructor of $(D_PARAM T).
+ *
+ * Params:
+ *  T         = Type of the constructed object.
+ *  A         = Types of the arguments to the constructor of $(D_PARAM T).
+ *  allocator = Allocator.
+ *  args      = Constructor arguments of $(D_PARAM T).
+ * 
+ * Returns: Newly created $(D_PSYMBOL Unique!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null)
+ */
+Unique!T unique(T, A...)(shared Allocator allocator, auto ref A args)
+    if (!is(T == interface) && !isAbstractClass!T
+     && !isAssociativeArray!T && !isArray!T)
+in
+{
+    assert(allocator !is null);
+}
+body
+{
+    auto payload = allocator.make!(T, shared Allocator, A)(args);
+    return Unique!T(payload, allocator);
+}
+
+/**
+ * Constructs a new array with $(D_PARAM size) elements and wraps it in a
+ * $(D_PSYMBOL Unique).
+ *
+ * Params:
+ *  T         = Array type.
+ *  size      = Array size.
+ *  allocator = Allocator.
+ *
+ * Returns: Newly created $(D_PSYMBOL Unique!T).
+ *
+ * Precondition: $(D_INLINECODE allocator !is null
+ *                           && size <= size_t.max / ElementType!T.sizeof)
+ */
+Unique!T unique(T)(shared Allocator allocator, const size_t size)
+@trusted
+    if (isArray!T)
+in
+{
+    assert(allocator !is null);
+    assert(size <= size_t.max / ElementType!T.sizeof);
+}
+body
+{
+    auto payload = allocator.resize!(ElementType!T)(null, size);
+    return Unique!T(payload, allocator);
+}
+
+private unittest
+{
+    static assert(is(typeof(defaultAllocator.unique!B(5))));
+    static assert(is(typeof(defaultAllocator.unique!(int[])(5))));
+}
+
+private unittest
+{
+    auto s = defaultAllocator.unique!int(5);
+    assert(*s == 5);
+
+    s = null;
+    assert(s is null);
+}
+
+private unittest
+{
+    auto s = defaultAllocator.unique!int(5);
+    assert(*s == 5);
+
+    s = defaultAllocator.unique!int(4);
+    assert(*s == 4);
+}
+
+private @nogc unittest
+{
+    auto p1 = defaultAllocator.make!int(5);
+    auto p2 = p1;
+    auto rc = Unique!int(p1, defaultAllocator);
+
+    assert(p1 is null);
+    assert(rc.get() is p2);
+}
+
+private @nogc unittest
+{
+    auto rc = Unique!int(defaultAllocator);
+    assert(rc.allocator is defaultAllocator);
+}

source/tanya/memory/types.d

@@ -3,11 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
+ * Smart pointers.
+ *
+ * $(RED Deprecated. Use $(D_PSYMBOL tanya.memory.smartref) instead.
+ * This module will be removed in 0.8.0.)
+ *
  * Copyright: Eugene Wissner 2016-2017.
  * 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)
  */
+deprecated("Use tanya.memory.smartref instead")
 module tanya.memory.types;
 
 import core.exception;
@@ -17,318 +23,10 @@ import std.conv;
 import std.range;
 import std.traits;
 import tanya.memory;
-
+public import tanya.memory.smartref : RefCounted, Payload;
-private template Payload(T)
-{
-    static if (is(T == class) || is(T == interface) || isArray!T)
-    {
-        alias Payload = T;
-    }
-    else
-    {
-        alias Payload = T*;
-    }
-}
-
-final class RefCountedStore(T)
-{
-    T payload;
-    size_t counter = 1;
-
-    size_t opUnary(string op)()
-        if (op == "--" || op == "++")
-    in
-    {
-        assert(counter > 0);
-    }
-    body
-    {
-        mixin("return " ~ op ~ "counter;");
-    }
-
-    int opCmp(const size_t counter)
-    {
-        if (this.counter > counter)
-        {
-            return 1;
-        }
-        else if (this.counter < counter)
-        {
-            return -1;
-        }
-        else
-        {
-            return 0;
-        }
-    }
-
-    int opEquals(const size_t counter)
-    {
-        return this.counter == counter;
-    }
-}
-
-private void separateDeleter(T)(RefCountedStore!T storage,
-                                shared Allocator allocator)
-{
-    allocator.dispose(storage.payload);
-    allocator.dispose(storage);
-}
-
-private void unifiedDeleter(T)(RefCountedStore!T storage,
-                               shared Allocator allocator)
-{
-    auto ptr1 = finalize(storage);
-    auto ptr2 = finalize(storage.payload);
-    allocator.deallocate(ptr1.ptr[0 .. ptr1.length + ptr2.length]);
-}
-
-/**
- * Reference-counted object containing a $(D_PARAM T) value as payload.
- * $(D_PSYMBOL RefCounted) keeps track of all references of an object, and
- * when the reference count goes down to zero, frees the underlying store.
- *
- * Params:
- *  T = Type of the reference-counted value.
- */
-struct RefCounted(T)
-{
-    private alias Storage = RefCountedStore!(Payload!T);
-
-    private Storage storage;
-    private void function(Storage storage,
-                          shared Allocator allocator) @nogc deleter;
-
-    invariant
-    {
-        assert(storage is null || allocator_ !is null);
-        assert(storage is null || deleter !is null);
-    }
-
-    /**
-     * Takes ownership over $(D_PARAM value), setting the counter to 1.
-     * $(D_PARAM value) may be a pointer, an object or a dynamic array.
-     *
-     * Params:
-     *  value     = Value whose ownership is taken over.
-     *  allocator = Allocator used to destroy the $(D_PARAM value) and to
-     *              allocate/deallocate internal storage.
-     *
-     * Precondition: $(D_INLINECODE allocator !is null)
-     */
-    this()(auto ref Payload!T value,
-           shared Allocator allocator = defaultAllocator)
-    {
-        this(allocator);
-        this.storage = allocator.make!Storage();
-        this.deleter = &separateDeleter!(Payload!T);
-
-        move(value, this.storage.payload);
-        static if (__traits(isRef, value))
-        {
-            value = null;
-        }
-    }
-
-    /// Ditto.
-    this(shared Allocator allocator)
-    in
-    {
-        assert(allocator !is null);
-    }
-    body
-    {
-        this.allocator_ = allocator;
-    }
-
-    /**
-     * Increases the reference counter by one.
-     */
-    this(this)
-    {
-        if (count != 0)
-        {
-            ++this.storage;
-        }
-    }
-
-    /**
-     * Decreases the reference counter by one.
-     *
-     * If the counter reaches 0, destroys the owned object.
-     */
-    ~this()
-    {
-        if (this.storage !is null && !(this.storage.counter && --this.storage))
-        {
-            deleter(this.storage, allocator);
-        }
-    }
-
-    /**
-     * Takes ownership over $(D_PARAM rhs). Initializes this
-     * $(D_PSYMBOL RefCounted) if needed.
-     *
-     * If it is the last reference of the previously owned object,
-     * it will be destroyed.
-     *
-     * To reset $(D_PSYMBOL RefCounted) assign $(D_KEYWORD null).
-     *
-     * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
-     * be used. If you need a different allocator, create a new
-     * $(D_PSYMBOL RefCounted) and assign it.
-     *
-     * Params:
-     *  rhs = New object.
-     *
-     * Returns: $(D_KEYWORD this).
-     */
-    ref typeof(this) opAssign()(auto ref Payload!T rhs)
-    {
-        if (this.storage is null)
-        {
-            this.storage = allocator.make!Storage();
-            this.deleter = &separateDeleter!(Payload!T);
-        }
-        else if (this.storage > 1)
-        {
-            --this.storage;
-            this.storage = allocator.make!Storage();
-            this.deleter = &separateDeleter!(Payload!T);
-        }
-        else
-        {
-            finalize(this.storage.payload);
-            this.storage.payload = Payload!T.init;
-        }
-        move(rhs, this.storage.payload);
-        return this;
-    }
-
-    /// Ditto.
-    ref typeof(this) opAssign(typeof(null))
-    {
-        if (this.storage is null)
-        {
-            return this;
-        }
-        else if (this.storage > 1)
-        {
-            --this.storage;
-        }
-        else
-        {
-            deleter(this.storage, allocator);
-        }
-        this.storage = null;
-
-        return this;
-    }
-
-    /// Ditto.
-    ref typeof(this) opAssign(typeof(this) rhs)
-    {
-        swap(this.allocator_, rhs.allocator_);
-        swap(this.storage, rhs.storage);
-        swap(this.deleter, rhs.deleter);
-        return this;
-    }
-
-    /**
-     * Returns: Reference to the owned object.
-     *
-     * Precondition: $(D_INLINECODE cound > 0).
-     */
-    Payload!T get() pure nothrow @safe @nogc
-    in
-    {
-        assert(count > 0, "Attempted to access an uninitialized reference.");
-    }
-    body
-    {
-        return storage.payload;
-    }
-
-    version (D_Ddoc)
-    {
-        /**
-         * Params:
-         *  op = Operation. 
-         *
-         * Dereferences the pointer. It is defined only for pointers, not for
-         * reference types like classes, that can be accessed directly.
-         *
-         * Returns: Reference to the pointed value.
-         */
-        ref T opUnary(string op)()
-            if (op == "*");
-    }
-    else static if (isPointer!(Payload!T))
-    {
-        ref T opUnary(string op)()
-            if (op == "*")
-        {
-            return *storage.payload;
-        }
-    }
-
-    /**
-     * Returns: Whether this $(D_PSYMBOL RefCounted) already has an internal 
-     *          storage.
-     */
-    @property bool isInitialized() const
-    {
-        return storage !is null;
-    }
-
-    /**
-     * Returns: The number of $(D_PSYMBOL RefCounted) instances that share
-     *          ownership over the same pointer (including $(D_KEYWORD this)).
-     *          If this $(D_PSYMBOL RefCounted) isn't initialized, returns `0`.
-     */
-    @property size_t count() const
-    {
-        return storage is null ? 0 : storage.counter;
-    }
-
-    mixin DefaultAllocator;
-    alias get this;
-}
-
-///
-unittest
-{
-    auto rc = RefCounted!int(defaultAllocator.make!int(5), defaultAllocator);
-    auto val = rc.get();
-
-    *val = 8;
-    assert(*rc.storage.payload == 8);
-
-    val = null;
-    assert(rc.storage.payload !is null);
-    assert(*rc.storage.payload == 8);
-
-    *rc = 9;
-    assert(*rc.storage.payload == 9);
-}
 
 version (unittest)
 {
-    private class A
-    {
-        uint *destroyed;
-
-        this(ref uint destroyed) @nogc
-        {
-            this.destroyed = &destroyed;
-        }
-
-        ~this() @nogc
-        {
-            ++(*destroyed);
-        }
-    }
-
     private struct B
     {
         int prop;
@@ -340,255 +38,13 @@ version (unittest)
     }
 }
 
-private @nogc unittest
-{
-    uint destroyed;
-    auto a = defaultAllocator.make!A(destroyed);
-
-    assert(destroyed == 0);
-    {
-        auto rc = RefCounted!A(a, defaultAllocator);
-        assert(rc.count == 1);
-
-        void func(RefCounted!A rc) @nogc
-        {
-            assert(rc.count == 2);
-        }
-        func(rc);
-
-        assert(rc.count == 1);
-    }
-    assert(destroyed == 1);
-
-    RefCounted!int rc;
-    assert(rc.count == 0);
-    rc = defaultAllocator.make!int(8);
-    assert(rc.count == 1);
-}
-
-private @nogc unittest
-{
-    auto rc = RefCounted!int(defaultAllocator);
-    assert(!rc.isInitialized);
-    assert(rc.allocator is defaultAllocator);
-}
-
-private @nogc unittest
-{
-    auto rc = defaultAllocator.refCounted!int(5);
-    assert(rc.count == 1);
-
-    void func(RefCounted!int rc) @nogc
-    {
-        assert(rc.count == 2);
-        rc = null;
-        assert(!rc.isInitialized);
-        assert(rc.count == 0);
-    }
-
-    assert(rc.count == 1);
-    func(rc);
-    assert(rc.count == 1);
-
-    rc = null;
-    assert(!rc.isInitialized);
-    assert(rc.count == 0);
-}
-
-private unittest
-{
-    auto rc = defaultAllocator.refCounted!int(5);
-    assert(*rc == 5);
-
-    void func(RefCounted!int rc) @nogc
-    {
-        assert(rc.count == 2);
-        rc = defaultAllocator.refCounted!int(4);
-        assert(*rc == 4);
-        assert(rc.count == 1);
-    }
-    func(rc);
-    assert(*rc == 5);
-}
-
-private unittest
-{
-    static assert(is(typeof(RefCounted!int.storage.payload) == int*));
-    static assert(is(typeof(RefCounted!A.storage.payload) == A));
-
-    static assert(is(RefCounted!B));
-    static assert(is(RefCounted!A));
-}
-
 /**
- * Constructs a new object of type $(D_PARAM T) and wraps it in a
+ * $(D_PSYMBOL Scoped) stores an object that gets destroyed at the end of its scope.
- * $(D_PSYMBOL RefCounted) using $(D_PARAM args) as the parameter list for
- * the constructor of $(D_PARAM T).
- *
- * This function is more efficient than the using of $(D_PSYMBOL RefCounted)
- * directly, since it allocates only ones (the internal storage and the
- * object).
- *
- * Params:
- *  T         = Type of the constructed object.
- *  A         = Types of the arguments to the constructor of $(D_PARAM T).
- *  allocator = Allocator.
- *  args      = Constructor arguments of $(D_PARAM T).
- * 
- * Returns: Newly created $(D_PSYMBOL RefCounted!T).
- *
- * Precondition: $(D_INLINECODE allocator !is null)
- */
-RefCounted!T refCounted(T, A...)(shared Allocator allocator, auto ref A args)
-    if (!is(T == interface) && !isAbstractClass!T
-     && !isAssociativeArray!T && !isArray!T)
-in
-{
-    assert(allocator !is null);
-}
-body
-{
-    auto rc = typeof(return)(allocator);
-
-    const storageSize = alignedSize(stateSize!(RefCounted!T.Storage));
-    const size = alignedSize(stateSize!T + storageSize);
-
-    auto mem = (() @trusted => allocator.allocate(size))();
-    if (mem is null)
-    {
-        onOutOfMemoryError();
-    }
-    scope (failure)
-    {
-        () @trusted { allocator.deallocate(mem); }();
-    }
-    rc.storage = emplace!((RefCounted!T.Storage))(mem[0 .. storageSize]);
-
-    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;
-}
-
-/**
- * Constructs a new array with $(D_PARAM size) elements and wraps it in a
- * $(D_PSYMBOL RefCounted).
- *
- * Params:
- *  T         = Array type.
- *  size      = Array size.
- *  allocator = Allocator.
- *
- * Returns: Newly created $(D_PSYMBOL RefCounted!T).
- *
- * Precondition: $(D_INLINECODE allocator !is null
- *                           && size <= size_t.max / ElementType!T.sizeof)
- */
-RefCounted!T refCounted(T)(shared Allocator allocator, const size_t size)
-@trusted
-    if (isArray!T)
-in
-{
-    assert(allocator !is null);
-    assert(size <= size_t.max / ElementType!T.sizeof);
-}
-body
-{
-    auto payload = allocator.resize!(ElementType!T)(null, size);
-    return RefCounted!T(payload, allocator);
-}
-
-///
-unittest
-{
-    auto rc = defaultAllocator.refCounted!int(5);
-    assert(rc.count == 1);
-
-    void func(RefCounted!int param) @nogc
-    {
-        if (param.count == 2)
-        {
-            func(param);
-        }
-        else
-        {
-            assert(param.count == 3);
-        }
-    }
-    func(rc);
-
-    assert(rc.count == 1);
-}
-
-private @nogc unittest
-{
-    struct E
-    {
-    }
-    auto b = defaultAllocator.refCounted!B(15);
-    static assert(is(typeof(b.storage.payload) == B*));
-    static assert(is(typeof(b.prop) == int));
-    static assert(!is(typeof(defaultAllocator.refCounted!B())));
-
-    static assert(is(typeof(defaultAllocator.refCounted!E())));
-    static assert(!is(typeof(defaultAllocator.refCounted!E(5))));
-    {
-        auto rc = defaultAllocator.refCounted!B(3);
-        assert(rc.get().prop == 3);
-    }
-    {
-        auto rc = defaultAllocator.refCounted!E();
-        assert(rc.count);
-    }
-}
-
-private @nogc unittest
-{
-    auto rc = defaultAllocator.refCounted!(int[])(5);
-    assert(rc.length == 5);
-}
-
-private @nogc unittest
-{
-    auto p1 = defaultAllocator.make!int(5);
-    auto p2 = p1;
-    auto rc = RefCounted!int(p1, defaultAllocator);
-
-    assert(p1 is null);
-    assert(rc.get() is p2);
-}
-
-private @nogc unittest
-{
-    static bool destroyed = false;
-
-    struct F
-    {
-        ~this() @nogc
-        {
-            destroyed = true;
-        }
-    }
-    {
-        auto rc = defaultAllocator.refCounted!F();
-    }
-    assert(destroyed);
-}
-
-/**
- * $(D_PSYMBOL Unique) stores an object that gets destroyed at the end of its scope.
  *
  * Params:
  *  T = Value type.
  */
-struct Unique(T)
+struct Scoped(T)
 {
     private Payload!T payload;
 
@@ -632,7 +88,7 @@ struct Unique(T)
     }
 
     /**
-     * $(D_PSYMBOL Unique) is noncopyable.
+     * $(D_PSYMBOL Scoped) is noncopyable.
      */
     @disable this(this);
 
@@ -648,14 +104,14 @@ struct Unique(T)
     }
 
     /**
-     * Initialized this $(D_PARAM Unique) and takes ownership over
+     * Initialized this $(D_PARAM Scoped) and takes ownership over
      * $(D_PARAM rhs).
      *
-     * To reset $(D_PSYMBOL Unique) assign $(D_KEYWORD null).
+     * To reset $(D_PSYMBOL Scoped) assign $(D_KEYWORD null).
      *
      * If the allocator wasn't set before, $(D_PSYMBOL defaultAllocator) will
      * be used. If you need a different allocator, create a new
-     * $(D_PSYMBOL Unique) and assign it.
+     * $(D_PSYMBOL Scoped) and assign it.
      *
      * Params:
      *  rhs = New object.
@@ -725,7 +181,7 @@ struct Unique(T)
 @nogc unittest
 {
     auto p = defaultAllocator.make!int(5);
-    auto s = Unique!int(p, defaultAllocator);
+    auto s = Scoped!int(p, defaultAllocator);
     assert(p is null);
     assert(*s == 5);
 }
@@ -743,14 +199,14 @@ struct Unique(T)
         }
     }
     {
-        auto s = Unique!F(defaultAllocator.make!F(), defaultAllocator);
+        auto s = Scoped!F(defaultAllocator.make!F(), defaultAllocator);
     }
     assert(destroyed);
 }
 
 /**
  * Constructs a new object of type $(D_PARAM T) and wraps it in a
- * $(D_PSYMBOL Unique) using $(D_PARAM args) as the parameter list for
+ * $(D_PSYMBOL Scoped) using $(D_PARAM args) as the parameter list for
  * the constructor of $(D_PARAM T).
  *
  * Params:
@@ -759,11 +215,11 @@ struct Unique(T)
  *  allocator = Allocator.
  *  args      = Constructor arguments of $(D_PARAM T).
  * 
- * Returns: Newly created $(D_PSYMBOL Unique!T).
+ * Returns: Newly created $(D_PSYMBOL Scoped!T).
  *
  * Precondition: $(D_INLINECODE allocator !is null)
  */
-Unique!T unique(T, A...)(shared Allocator allocator, auto ref A args)
+Scoped!T scoped(T, A...)(shared Allocator allocator, auto ref A args)
     if (!is(T == interface) && !isAbstractClass!T
      && !isAssociativeArray!T && !isArray!T)
 in
@@ -773,24 +229,24 @@ in
 body
 {
     auto payload = allocator.make!(T, shared Allocator, A)(args);
-    return Unique!T(payload, allocator);
+    return Scoped!T(payload, allocator);
 }
 
 /**
  * Constructs a new array with $(D_PARAM size) elements and wraps it in a
- * $(D_PSYMBOL Unique).
+ * $(D_PSYMBOL Scoped).
  *
  * Params:
  *  T         = Array type.
  *  size      = Array size.
  *  allocator = Allocator.
  *
- * Returns: Newly created $(D_PSYMBOL Unique!T).
+ * Returns: Newly created $(D_PSYMBOL Scoped!T).
  *
  * Precondition: $(D_INLINECODE allocator !is null
  *                           && size <= size_t.max / ElementType!T.sizeof)
  */
-Unique!T unique(T)(shared Allocator allocator, const size_t size)
+Scoped!T scoped(T)(shared Allocator allocator, const size_t size)
 @trusted
     if (isArray!T)
 in
@@ -801,18 +257,18 @@ in
 body
 {
     auto payload = allocator.resize!(ElementType!T)(null, size);
-    return Unique!T(payload, allocator);
+    return Scoped!T(payload, allocator);
 }
 
 private unittest
 {
-    static assert(is(typeof(defaultAllocator.unique!B(5))));
+    static assert(is(typeof(defaultAllocator.scoped!B(5))));
-    static assert(is(typeof(defaultAllocator.unique!(int[])(5))));
+    static assert(is(typeof(defaultAllocator.scoped!(int[])(5))));
 }
 
 private unittest
 {
-    auto s = defaultAllocator.unique!int(5);
+    auto s = defaultAllocator.scoped!int(5);
     assert(*s == 5);
 
     s = null;
@@ -821,10 +277,10 @@ private unittest
 
 private unittest
 {
-    auto s = defaultAllocator.unique!int(5);
+    auto s = defaultAllocator.scoped!int(5);
     assert(*s == 5);
 
-    s = defaultAllocator.unique!int(4);
+    s = defaultAllocator.scoped!int(4);
     assert(*s == 4);
 }
 
@@ -832,7 +288,7 @@ private @nogc unittest
 {
     auto p1 = defaultAllocator.make!int(5);
     auto p2 = p1;
-    auto rc = Unique!int(p1, defaultAllocator);
+    auto rc = Scoped!int(p1, defaultAllocator);
 
     assert(p1 is null);
     assert(rc.get() is p2);
@@ -840,17 +296,6 @@ private @nogc unittest
 
 private @nogc unittest
 {
-    auto rc = Unique!int(defaultAllocator);
+    auto rc = Scoped!int(defaultAllocator);
     assert(rc.allocator is defaultAllocator);
 }
-
-/**
- * $(RED Deprecated. Use $(D_PSYMBOL Unique) and $(D_PSYMBOL unique) instead.
- * These aliases will be removed in 0.8.0.)
- */
-deprecated("Use Unique instead")
-alias Scoped = Unique;
-
-/// Ditto.
-deprecated("Use unique instead")
-alias scoped = unique;