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 <__cstddef/ptrdiff_t.h> 15 #include <__cstddef/size_t.h> 16 #include <__type_traits/common_type.h> 17 #include <__type_traits/make_signed.h> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 # pragma GCC system_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 #if _LIBCPP_STD_VER >= 17 26 27 template <class _Cont> 28 _LIBCPP_HIDE_FROM_ABI constexpr auto size(const _Cont& __c) noexcept(noexcept(__c.size())) -> decltype(__c.size()) { 29 return __c.size(); 30 } 31 32 template <class _Tp, size_t _Sz> 33 _LIBCPP_HIDE_FROM_ABI constexpr size_t size(const _Tp (&)[_Sz]) noexcept { 34 return _Sz; 35 } 36 37 # if _LIBCPP_STD_VER >= 20 38 template <class _Cont> 39 _LIBCPP_HIDE_FROM_ABI constexpr auto 40 ssize(const _Cont& __c) noexcept(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>( 41 __c.size()))) -> common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>> { 42 return static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); 43 } 44 45 // GCC complains about the implicit conversion from ptrdiff_t to size_t in 46 // the array bound. 47 _LIBCPP_DIAGNOSTIC_PUSH 48 _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wsign-conversion") 49 template <class _Tp, ptrdiff_t _Sz> 50 _LIBCPP_HIDE_FROM_ABI constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { 51 return _Sz; 52 } 53 _LIBCPP_DIAGNOSTIC_POP 54 # endif 55 56 #endif // _LIBCPP_STD_VER >= 17 57 58 _LIBCPP_END_NAMESPACE_STD 59 60 #endif // _LIBCPP___ITERATOR_SIZE_H 61