Make AllocaAppender forward compatible with current std.experimental.…

…allocator.

Up to now, was relying on the old stdx.allocator interface that used IAllocator for passing around allocators as objects. The current version uses RCIAllocator instead.

source/vibe/internal/array.d

@@ -46,6 +46,8 @@ struct AllocAppender(ArrayType : E[], E) {
 		ElemType[] m_data;
 		ElemType[] m_remaining;
 		IAllocator m_alloc;
+		static if (is(RCIAllocator))
+			RCIAllocator m_rcAlloc;
 		bool m_allocatedBuffer = false;
 	}
 
@@ -56,14 +58,23 @@ struct AllocAppender(ArrayType : E[], E) {
 		m_remaining = initial_buffer;
 	}
 
+	static if (is(RCIAllocator)) {
+		this(RCIAllocator alloc, ElemType[] initial_buffer = null)
+		@safe {
+			m_rcAlloc = alloc;
+			m_data = initial_buffer;
+			m_remaining = initial_buffer;
+		}
+	}
+
 	@disable this(this);
 
 	@property ArrayType data() { return cast(ArrayType)m_data[0 .. m_data.length - m_remaining.length]; }
 
 	void reset(AppenderResetMode reset_mode = AppenderResetMode.keepData)
 	{
 		if (reset_mode == AppenderResetMode.keepData) m_data = null;
-		else if (reset_mode == AppenderResetMode.freeData) { if (m_allocatedBuffer) m_alloc.deallocate(m_data); m_data = null; }
+		else if (reset_mode == AppenderResetMode.freeData) { if (m_allocatedBuffer) withAlloc!"deallocate"(m_data); m_data = null; }
 		m_remaining = m_data;
 	}
 
@@ -78,7 +89,7 @@ struct AllocAppender(ArrayType : E[], E) {
 	@safe {
 		size_t nelems = m_data.length - m_remaining.length;
 		if (!m_data.length) {
-			m_data = () @trusted { return cast(ElemType[])m_alloc.allocate(amount*E.sizeof); } ();
+			m_data = () @trusted { return cast(ElemType[])withAlloc!"allocate"(amount*E.sizeof); } ();
 			m_remaining = m_data;
 			m_allocatedBuffer = true;
 		}
@@ -89,10 +100,10 @@ struct AllocAppender(ArrayType : E[], E) {
 			}
 			if (m_allocatedBuffer) () @trusted {
 				auto vdata = cast(void[])m_data;
-				m_alloc.reallocate(vdata, (nelems+amount)*E.sizeof);
+				withAlloc!"reallocate"(vdata, (nelems+amount)*E.sizeof);
 				m_data = cast(ElemType[])vdata;
 			} (); else {
-				auto newdata = () @trusted { return cast(ElemType[])m_alloc.allocate((nelems+amount)*E.sizeof); } ();
+				auto newdata = () @trusted { return cast(ElemType[])withAlloc!"allocate"((nelems+amount)*E.sizeof); } ();
 				newdata[0 .. nelems] = m_data[0 .. nelems];
 				m_data = newdata;
 				m_allocatedBuffer = true;
@@ -173,6 +184,15 @@ struct AllocAppender(ArrayType : E[], E) {
 			new_size = (new_size * 3) / 2;
 		reserve(new_size - m_data.length + m_remaining.length);
 	}
+
+	private auto withAlloc(string method, ARGS...)(ARGS args)
+	{
+		static if (is(RCIAllocator)) {
+			if (!m_rcAlloc.isNull) return __traits(getMember, m_rcAlloc, method)(args);
+		}
+		if (m_alloc) return __traits(getMember, m_alloc, method)(args);
+		assert(false, "Using AllocAppender with no allocator set");
+	}
 }
 
 unittest {