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Diffstat (limited to 'libcxx/include/__iterator/distance.h')
-rw-r--r-- | libcxx/include/__iterator/distance.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/libcxx/include/__iterator/distance.h b/libcxx/include/__iterator/distance.h new file mode 100644 index 000000000000..33e4af84d36e --- /dev/null +++ b/libcxx/include/__iterator/distance.h @@ -0,0 +1,56 @@ +// -*- 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_PUSH_MACROS +#include <__undef_macros> + +_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 + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___ITERATOR_DISTANCE_H |