368faacac7
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9, which were related to the original commit). As landed, 5aaefa51 had unintended consequences on some downstream bots and didn't have proper coverage upstream due to a few subtle things. Implementing this is something we should do in libc++, however we'll first need to address a few issues listed in https://reviews.llvm.org/D106124#3349710. Differential Revision: https://reviews.llvm.org/D120683
61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
// -*- C++ -*-
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___MEMORY_USES_ALLOCATOR_H
|
|
#define _LIBCPP___MEMORY_USES_ALLOCATOR_H
|
|
|
|
#include <__config>
|
|
#include <cstddef>
|
|
#include <type_traits>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
template <class _Tp>
|
|
struct __has_allocator_type
|
|
{
|
|
private:
|
|
struct __two {char __lx; char __lxx;};
|
|
template <class _Up> static __two __test(...);
|
|
template <class _Up> static char __test(typename _Up::allocator_type* = 0);
|
|
public:
|
|
static const bool value = sizeof(__test<_Tp>(0)) == 1;
|
|
};
|
|
|
|
template <class _Tp, class _Alloc, bool = __has_allocator_type<_Tp>::value>
|
|
struct __uses_allocator
|
|
: public integral_constant<bool,
|
|
is_convertible<_Alloc, typename _Tp::allocator_type>::value>
|
|
{
|
|
};
|
|
|
|
template <class _Tp, class _Alloc>
|
|
struct __uses_allocator<_Tp, _Alloc, false>
|
|
: public false_type
|
|
{
|
|
};
|
|
|
|
template <class _Tp, class _Alloc>
|
|
struct _LIBCPP_TEMPLATE_VIS uses_allocator
|
|
: public __uses_allocator<_Tp, _Alloc>
|
|
{
|
|
};
|
|
|
|
#if _LIBCPP_STD_VER > 14
|
|
template <class _Tp, class _Alloc>
|
|
inline constexpr size_t uses_allocator_v = uses_allocator<_Tp, _Alloc>::value;
|
|
#endif
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___MEMORY_USES_ALLOCATOR_H
|