1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // <iterator> 10 11 // All of these became constexpr in C++17 12 // 13 // template <InputIterator Iter> 14 // constexpr void advance(Iter& i, Iter::difference_type n); 15 // 16 // template <BidirectionalIterator Iter> 17 // constexpr void advance(Iter& i, Iter::difference_type n); 18 // 19 // template <RandomAccessIterator Iter> 20 // constexpr void advance(Iter& i, Iter::difference_type n); 21 22 #include <iterator> 23 #include <cassert> 24 #include <type_traits> 25 26 #include "test_macros.h" 27 #include "test_iterators.h" 28 29 template <class It> 30 TEST_CONSTEXPR_CXX17 31 void check_advance(It it, typename std::iterator_traits<It>::difference_type n, It result) 32 { 33 static_assert(std::is_same<decltype(std::advance(it, n)), void>::value, ""); 34 std::advance(it, n); 35 assert(it == result); 36 } 37 38 TEST_CONSTEXPR_CXX17 bool tests() 39 { 40 const char* s = "1234567890"; 41 check_advance(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10)); 42 check_advance(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10)); 43 check_advance(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10)); 44 check_advance(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s)); 45 check_advance(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10)); 46 check_advance(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s)); 47 check_advance(s+5, 5, s+10); 48 check_advance(s+5, -5, s); 49 50 return true; 51 } 52 53 int main(int, char**) 54 { 55 tests(); 56 #if TEST_STD_VER >= 17 57 static_assert(tests(), ""); 58 #endif 59 return 0; 60 } 61