[ox/std] Add is_move_constructible

deps/ox/src/ox/std/CMakeLists.txt

@@ -34,6 +34,7 @@ add_library(
 		string.cpp
 		strops.cpp
 		trace.cpp
+		typetraits.cpp
 )
 
 if(NOT MSVC)

deps/ox/src/ox/std/memory.hpp

@@ -50,14 +50,13 @@ void safeDeleteArray(auto *val) requires(sizeof(*val) >= 1) {
 	delete[] val;
 }
 
-template<typename T>
 struct DefaultDelete {
-	constexpr void operator()(T *p) noexcept {
+	constexpr void operator()(auto *p) noexcept {
 		safeDelete(p);
 	}
 };
 
-template<typename T, typename Deleter = DefaultDelete<T>>
+template<typename T, typename Deleter = DefaultDelete>
 class UniquePtr {
 
 	private:

deps/ox/src/ox/std/typetraits.cpp

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2015 - 2022 gary@drinkingtea.net
+ *
+ * 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/.
+ */
+
+#include "typetraits.hpp"
+
+namespace ox {
+
+template<bool moveable, bool copyable>
+struct ConstructableTest {
+	constexpr ConstructableTest(int) noexcept {}
+	constexpr ConstructableTest(ConstructableTest&) noexcept requires(copyable) {}
+	constexpr ConstructableTest(ConstructableTest&&) noexcept requires(moveable) {}
+};
+
+static_assert(!is_move_constructible_v<ConstructableTest<false, false>>);
+static_assert(is_move_constructible_v<ConstructableTest<true, false>>);
+static_assert(!is_move_constructible_v<ConstructableTest<false, true>>);
+static_assert(is_move_constructible_v<ConstructableTest<true, true>>);
+
+}

deps/ox/src/ox/std/typetraits.hpp

@@ -182,4 +182,22 @@ struct remove_reference<T&&> {
 template<typename T>
 using remove_reference_t = typename remove_reference<T>::type;
 
+namespace detail {
+template<typename T>
+T &&declval();
+
+template<typename T, typename = decltype(T(declval<T>()))>
+constexpr bool is_move_constructible(int) {
+	return true;
+}
+
+template<typename T>
+constexpr bool is_move_constructible(bool) {
+	return false;
+}
+}
+
+template<class T>
+constexpr bool is_move_constructible_v = detail::is_move_constructible<T>(0);
+
 }