libcxx/include/__iterator/size.h

   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>
  15 #include <type_traits>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #pragma GCC system_header
  19 #endif
  20
  21 _LIBCPP_BEGIN_NAMESPACE_STD
  22
  23 #if _LIBCPP_STD_VER > 14
  24
  25 template <class _Cont>
  26 _LIBCPP_INLINE_VISIBILITY
  27 constexpr auto size(const _Cont& __c)
  28 _NOEXCEPT_(noexcept(__c.size()))
  29 -> decltype        (__c.size())
  30 { return            __c.size(); }
  31
  32 template <class _Tp, size_t _Sz>
  33 _LIBCPP_INLINE_VISIBILITY
  34 constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
  35
  36 #if _LIBCPP_STD_VER > 17
  37 template <class _Cont>
  38 _LIBCPP_INLINE_VISIBILITY
  39 constexpr auto ssize(const _Cont& __c)
  40 _NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size())))
  41 ->                              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 template <class _Tp, ptrdiff_t _Sz>
  45 _LIBCPP_INLINE_VISIBILITY
  46 constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; }
  47 #endif
  48
  49 #endif // _LIBCPP_STD_VER > 14
  50
  51 _LIBCPP_END_NAMESPACE_STD
  52
  53 #endif // _LIBCPP___ITERATOR_SIZE_H