| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___ITERATOR_DISTANCE_H |
| #define _LIBCPP___ITERATOR_DISTANCE_H |
| |
| #include <__config> |
| #include <__iterator/iterator_traits.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _InputIter> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| typename iterator_traits<_InputIter>::difference_type |
| __distance(_InputIter __first, _InputIter __last, input_iterator_tag) |
| { |
| typename iterator_traits<_InputIter>::difference_type __r(0); |
| for (; __first != __last; ++__first) |
| ++__r; |
| return __r; |
| } |
| |
| template <class _RandIter> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| typename iterator_traits<_RandIter>::difference_type |
| __distance(_RandIter __first, _RandIter __last, random_access_iterator_tag) |
| { |
| return __last - __first; |
| } |
| |
| template <class _InputIter> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| typename iterator_traits<_InputIter>::difference_type |
| distance(_InputIter __first, _InputIter __last) |
| { |
| return _VSTD::__distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category()); |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ITERATOR_DISTANCE_H |