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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-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___CXX03___ITERATOR_DISTANCE_H11#define _LIBCPP___CXX03___ITERATOR_DISTANCE_H12 13#include <__cxx03/__config>14#include <__cxx03/__iterator/iterator_traits.h>15#include <__cxx03/__type_traits/decay.h>16#include <__cxx03/__type_traits/remove_cvref.h>17 18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)19# pragma GCC system_header20#endif21 22_LIBCPP_BEGIN_NAMESPACE_STD23 24template <class _InputIter>25inline _LIBCPP_HIDE_FROM_ABI typename iterator_traits<_InputIter>::difference_type26__distance(_InputIter __first, _InputIter __last, input_iterator_tag) {27 typename iterator_traits<_InputIter>::difference_type __r(0);28 for (; __first != __last; ++__first)29 ++__r;30 return __r;31}32 33template <class _RandIter>34inline _LIBCPP_HIDE_FROM_ABI typename iterator_traits<_RandIter>::difference_type35__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag) {36 return __last - __first;37}38 39template <class _InputIter>40inline _LIBCPP_HIDE_FROM_ABI typename iterator_traits<_InputIter>::difference_type41distance(_InputIter __first, _InputIter __last) {42 return std::__distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());43}44 45_LIBCPP_END_NAMESPACE_STD46 47#endif // _LIBCPP___CXX03___ITERATOR_DISTANCE_H48