1 files changed, 69 insertions, 0 deletions
diff --git a/source/tanya/memory/package.d b/source/tanya/memory/package.d
index a524504..7c288da 100644
--- a/source/tanya/memory/package.d
+++ b/source/tanya/memory/package.d
@@ -10,6 +10,75 @@
  */
 module tanya.memory;
 
+import std.algorithm.mutation;
 public import std.experimental.allocator;
 public import tanya.memory.allocator;
 public import tanya.memory.types;
+
+shared Allocator allocator;
+
+shared static this() nothrow @safe @nogc
+{
+	import tanya.memory.mmappool;
+	allocator = MmapPool.instance;
+}
+
+@property ref shared(Allocator) defaultAllocator() nothrow @safe @nogc
+{
+	return allocator;
+}
+
+@property void defaultAllocator(shared(Allocator) allocator) nothrow @safe @nogc
+{
+	.allocator = allocator;
+}
+
+/**
+ * Params:
+ * 	T         = Element type of the array being created.
+ * 	allocator = The allocator used for getting memory.
+ * 	array     = A reference to the array being changed.
+ * 	length    = New array length.
+ * 	init      = The value to fill the new part of the array with if it becomes
+ * 	            larger.
+ *
+ * Returns: $(D_KEYWORD true) upon success, $(D_KEYWORD false) if memory could
+ *          not be reallocated. In the latter
+ */
+bool resizeArray(T)(shared Allocator allocator,
+                    ref T[] array,
+                    in size_t length,
+                    T init = T.init)
+{
+	void[] buf = array;
+	immutable oldLength = array.length;
+
+	if (!allocator.reallocate(buf, length * T.sizeof))
+	{
+		return false;
+	}
+	array = cast(T[]) buf;
+	if (oldLength < length)
+	{
+		array[oldLength .. $].uninitializedFill(init);
+	}
+	return true;
+}
+
+///
+unittest
+{
+	int[] p;
+
+	defaultAllocator.resizeArray(p, 20);
+	assert(p.length == 20);
+
+	defaultAllocator.resizeArray(p, 30);
+	assert(p.length == 30);
+
+	defaultAllocator.resizeArray(p, 10);
+	assert(p.length == 10);
+
+	defaultAllocator.resizeArray(p, 0);
+	assert(p is null);
+}