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 26 template <class _Cont> 27 _LIBCPP_INLINE_VISIBILITY 28 constexpr auto size(const _Cont& __c) 29 _NOEXCEPT_(noexcept(__c.size())) 30 -> decltype (__c.size()) 31 { return __c.size(); } 32 33 template <class _Tp, size_t _Sz> 34 _LIBCPP_INLINE_VISIBILITY 35 constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; } 36 37 #if _LIBCPP_STD_VER >= 20 38 template <class _Cont> 39 _LIBCPP_INLINE_VISIBILITY 40 constexpr auto ssize(const _Cont& __c) 41 _NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()))) 42 -> common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>> 43 { return static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); } 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_INLINE_VISIBILITY 51 constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; } 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