The usual commit from 1 year later with changes that I don't recognise

include/vectorwrapper/forward_wrapper.hpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2015-2018 Michele "King_DuckZ" Santullo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#if defined VWR_OUTER_NAMESPACE
+namespace VWR_OUTER_NAMESPACE {
+#endif
+
+namespace vwr {
+	template <typename V, typename Storage>
+	class forward_wrapper {
+	public:
+		forward_wrapper() { new(&m_storage) V; }
+		forward_wrapper (const forward_wrapper&) = delete;
+		forward_wrapper (forward_wrapper&&) = delete;
+		~forward_wrapper() { vector().~V(); }
+
+		forward_wrapper& operator= (const forward_wrapper&) = delete;
+		forward_wrapper& operator= (forward_wrapper&&) = delete;
+
+	private:
+		V& vector() { return *reinterpret_cast<V*>(&m_storage); }
+		//const V& vector() const { return *reinterpret_cast<const V*>(&m_storage); }
+
+		Storage m_storage;
+	};
+} //namespace vwr
+
+#if defined VWR_OUTER_NAMESPACE
+} //namespace VWR_OUTER_NAMESPACE
+#endif

test/unit/test_custom_storage.cpp

@@ -15,6 +15,7 @@
  */
 
 #include "vectorwrapper/vectorwrapper.hpp"
+#include "vectorwrapper/forward_wrapper.hpp"
 #include <gtest/gtest.h>
 
 namespace {

testme.cpp

@@ -0,0 +1,41 @@
+#include <iostream>
+
+template <typename T>
+int get_at (const T&, int);
+
+struct XY {
+	int x, y;
+};
+
+template <> int get_at(const int(&in)[2], int i) { return in[i]; }
+template <> int get_at(const XY& in, int i) { return (i ? in.y : in.x); }
+
+template <typename T>
+struct Vec {
+	int x() const { return get_at(m_storage_type, 0); }
+	int y() const { return get_at(m_storage_type, 1); }
+
+	T m_storage_type;
+};
+
+template <typename T>
+std::ostream& operator<< (std::ostream& os, const Vec<T>& v) {
+	os << '<' << v.x() << ',' << v.y() << '>';
+	return os;
+}
+
+int main() {
+	Vec<int[2]> v1;
+	Vec<XY> v2;
+
+	v1.m_storage_type[0] = 1234;
+	v1.m_storage_type[1] = 7777;
+
+	v2.m_storage_type.x = 44;
+	v2.m_storage_type.y = 9999;
+
+	std::cout << v1 << '\n';
+	std::cout << v2 << '\n';
+
+	return 0;
+}