Add noop deleter

Signed-off-by: Simon Rozman <simon@rozman.si>

include/stdex/memory.h

@@ -0,0 +1,52 @@
+/*
+	SPDX-License-Identifier: MIT
+	Copyright © 2023 Amebis
+*/
+
+#pragma once
+
+#include <memory>
+
+namespace stdex
+{
+	///
+	/// Noop deleter
+	///
+	template <class T>
+	struct no_delete {
+		constexpr no_delete() noexcept = default;
+
+		template <class T2, std::enable_if_t<std::is_convertible_v<T2*, T*>, int> = 0>
+		inline no_delete(const no_delete<T2>&) noexcept {}
+
+		inline void operator()(T* p) const noexcept { p; }
+	};
+
+	///
+	/// Noop array deleter
+	///
+	template <class T>
+	struct no_delete<T[]> {
+		constexpr no_delete() noexcept = default;
+
+		template <class _Uty, std::enable_if_t<std::is_convertible_v<_Uty(*)[], T(*)[]>, int> = 0>
+		inline no_delete(const no_delete<_Uty[]>&) noexcept {}
+
+		template <class _Uty, std::enable_if_t<std::is_convertible_v<_Uty(*)[], T(*)[]>, int> = 0>
+		inline void operator()(_Uty* p) const noexcept { p; }
+	};
+
+	///
+	/// Create shared_ptr with noop deleter.
+	///
+	/// This may be used to wrap data on stack in a shared_ptr. However, be extra careful
+	/// that shared_ptr is completely dereferenced _before_ stack data goes out of scope.
+	///
+	/// \param[in] p  Pointer to assign to shared_ptr
+	///
+	template <class T>
+	inline std::shared_ptr<T> make_shared_no_delete(_In_ T* p)
+	{
+		return std::shared_ptr<T>(p, no_delete<T>{});
+	}
+}