memory: Add overaligned_unique_ptr

include/mcl/memory/overaligned_unique_ptr.hpp

@@ -0,0 +1,46 @@
+// This file is part of the mcl project.
+// Copyright (c) 2022 merryhime
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include <type_traits>
+
+#ifdef _MSC_VER
+#    include <malloc.h>
+#else
+#    include <cstdlib>
+#endif
+
+namespace mcl {
+
+namespace detail {
+struct aligned_alloc_deleter {
+    template<typename T>
+    void operator()(T* p) const
+    {
+#ifdef _MSC_VER
+        _aligned_free(const_cast<std::remove_const_t<T>*>(p));
+#else
+        std::free(const_cast<std::remove_const_t<T>*>(p));
+#endif
+    }
+};
+}  // namespace detail
+
+template<size_t, typename T>
+using overaligned_unique_ptr = std::unique_ptr<T, detail::aligned_alloc_deleter>;
+
+template<size_t alignment, typename T>
+auto make_overaligned_unique_ptr_array(size_t element_count)
+{
+    const size_t min_size = element_count * sizeof(T);
+    const size_t alloc_size = (min_size + alignment - 1) / alignment * alignment;
+#ifdef _MSC_VER
+    return overaligned_unique_ptr<alignment, T[]>{static_cast<T*>(_aligned_malloc(alloc_size, alignment))};
+#else
+    return overaligned_unique_ptr<alignment, T[]>{static_cast<T*>(std::aligned_alloc(alignment, alloc_size))};
+#endif
+}
+
+}  // namespace mcl