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
54