libcruft-util/alloc/traits.hpp

79 lines
2.5 KiB
C++

/*
* 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/.
*
* Copyright 2018 Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include <type_traits>
namespace cruft::alloc {
///////////////////////////////////////////////////////////////////////////
/// A trait that evaluates to true if the queried type models cruft::allocator
template <
typename AllocatorT,
typename = std::void_t<>
>
struct is_allocator
: public std::false_type
{ };
//-------------------------------------------------------------------------
template <typename AllocatorT>
struct is_allocator<AllocatorT,
std::void_t<
// Provides aligned and unaligned allocation
decltype(std::declval<AllocatorT> ().allocate (0 )),
decltype(std::declval<AllocatorT> ().allocate (0, 0)),
//// Provides aligned an unaligned deallocation
decltype(std::declval<AllocatorT> ().deallocate (nullptr, 0)),
decltype(std::declval<AllocatorT> ().deallocate (nullptr, 0, 0)),
//// Provides capacity/used/remain
decltype(std::declval<AllocatorT> ().capacity ()),
decltype(std::declval<AllocatorT> ().used ()),
decltype(std::declval<AllocatorT> ().remain ()),
decltype(std::declval<AllocatorT> ().begin ()),
decltype(std::declval<AllocatorT> ().end ()),
void
>
> : public std::true_type
{ };
//-------------------------------------------------------------------------
template <typename AllocatorT>
constexpr auto is_allocator_v = is_allocator<AllocatorT>::value;
///////////////////////////////////////////////////////////////////////////
template <typename AllocT, typename = std::void_t<>>
struct has_aligned_allocate : std::false_type {};
//-------------------------------------------------------------------------
template <typename AllocT>
struct has_aligned_allocate<
AllocT,
std::void_t<
decltype (
std::declval<AllocT> ().allocate(16, 16)
)
>
>: public std::true_type {};
//-------------------------------------------------------------------------
template <typename AllocT>
constexpr auto has_aligned_allocate_v = has_aligned_allocate<AllocT>::value;
}