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___CXX03___ITERATOR_NEXT_H 11 #define _LIBCPP___CXX03___ITERATOR_NEXT_H 12 13 #include <__cxx03/__assert> 14 #include <__cxx03/__config> 15 #include <__cxx03/__iterator/advance.h> 16 #include <__cxx03/__iterator/iterator_traits.h> 17 #include <__cxx03/__type_traits/enable_if.h> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 # pragma GCC system_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0> 26 inline _LIBCPP_HIDE_FROM_ABI _InputIter 27 next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) { 28 // Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation. 29 // Note that this check duplicates the similar check in `std::advance`. 30 _LIBCPP_ASSERT_PEDANTIC(__n >= 0 || __has_bidirectional_iterator_category<_InputIter>::value, 31 "Attempt to next(it, n) with negative n on a non-bidirectional iterator"); 32 33 std::advance(__x, __n); 34 return __x; 35 } 36 37 _LIBCPP_END_NAMESPACE_STD 38 39 #endif // _LIBCPP___CXX03___ITERATOR_NEXT_H 40