Nikolas Klauser 88632e4806 [libc++] Refactor __less
This simplifies the usage of `__less` by making the class not depend on the types compared, but instead the `operator()`. We can't remove the template completely because we explicitly instantiate `std::__sort` with `__less<T>`.

Reviewed By: ldionne, #libc

Spies: arichardson, EricWF, libcxx-commits, mgrang

Differential Revision: https://reviews.llvm.org/D145285
2023-06-06 13:58:52 -07:00

48 lines
1.4 KiB
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___ALGORITHM_COMP_H
#define _LIBCPP___ALGORITHM_COMP_H
#include <__config>
#include <__type_traits/integral_constant.h>
#include <__type_traits/predicate_traits.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
struct __equal_to {
template <class _T1, class _T2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _T1& __x, const _T2& __y) const {
return __x == __y;
}
};
template <class _Lhs, class _Rhs>
struct __is_trivial_equality_predicate<__equal_to, _Lhs, _Rhs> : true_type {};
// The definition is required because __less is part of the ABI, but it's empty
// because all comparisons should be transparent.
template <class _T1 = void, class _T2 = _T1>
struct __less {};
template <>
struct __less<void, void> {
template <class _Tp, class _Up>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp& __lhs, const _Up& __rhs) const {
return __lhs < __rhs;
}
};
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___ALGORITHM_COMP_H