1// -*- C++ -*- 2//===----------------------------------------------------------------------===// 3// 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5// See https://llvm.org/LICENSE.txt for license information. 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7// 8//===----------------------------------------------------------------------===// 9 10#ifndef _LIBCPP___ITERATOR_SIZE_H 11#define _LIBCPP___ITERATOR_SIZE_H 12 13#include <__config> 14#include <__type_traits/common_type.h> 15#include <__type_traits/make_signed.h> 16#include <cstddef> 17 18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19# pragma GCC system_header 20#endif 21 22_LIBCPP_BEGIN_NAMESPACE_STD 23 24#if _LIBCPP_STD_VER >= 17 25 26template <class _Cont> 27_LIBCPP_HIDE_FROM_ABI constexpr auto size(const _Cont& __c) _NOEXCEPT_(noexcept(__c.size())) -> decltype(__c.size()) { 28 return __c.size(); 29} 30 31template <class _Tp, size_t _Sz> 32_LIBCPP_HIDE_FROM_ABI constexpr size_t size(const _Tp (&)[_Sz]) noexcept { 33 return _Sz; 34} 35 36# if _LIBCPP_STD_VER >= 20 37template <class _Cont> 38_LIBCPP_HIDE_FROM_ABI constexpr auto ssize(const _Cont& __c) 39 _NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()))) 40 -> common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>> { 41 return static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); 42} 43 44// GCC complains about the implicit conversion from ptrdiff_t to size_t in 45// the array bound. 46_LIBCPP_DIAGNOSTIC_PUSH 47_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wsign-conversion") 48template <class _Tp, ptrdiff_t _Sz> 49_LIBCPP_HIDE_FROM_ABI constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { 50 return _Sz; 51} 52_LIBCPP_DIAGNOSTIC_POP 53# endif 54 55#endif // _LIBCPP_STD_VER >= 17 56 57_LIBCPP_END_NAMESPACE_STD 58 59#endif // _LIBCPP___ITERATOR_SIZE_H 60