1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // <iterator>
11
12 // All of these became constexpr in C++17
13 //
14 // template <InputIterator Iter>
15 // constexpr void advance(Iter& i, Iter::difference_type n);
16 //
17 // template <BidirectionalIterator Iter>
18 // constexpr void advance(Iter& i, Iter::difference_type n);
19 //
20 // template <RandomAccessIterator Iter>
21 // constexpr void advance(Iter& i, Iter::difference_type n);
22
23 #include <iterator>
24 #include <cassert>
25
26 #include "test_iterators.h"
27
28 template <class It>
29 void
test(It i,typename std::iterator_traits<It>::difference_type n,It x)30 test(It i, typename std::iterator_traits<It>::difference_type n, It x)
31 {
32 std::advance(i, n);
33 assert(i == x);
34 }
35
36 #if TEST_STD_VER > 14
37 template <class It>
38 constexpr bool
constepxr_test(It i,typename std::iterator_traits<It>::difference_type n,It x)39 constepxr_test(It i, typename std::iterator_traits<It>::difference_type n, It x)
40 {
41 std::advance(i, n);
42 return i == x;
43 }
44 #endif
45
main()46 int main()
47 {
48 {
49 const char* s = "1234567890";
50 test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10));
51 test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10));
52 test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10));
53 test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s));
54 test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10));
55 test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s));
56 test(s+5, 5, s+10);
57 test(s+5, -5, s);
58 }
59 #if TEST_STD_VER > 14
60 {
61 constexpr const char* s = "1234567890";
62 static_assert( constepxr_test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10)), "" );
63 static_assert( constepxr_test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10)), "" );
64 static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10)), "" );
65 static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s)), "" );
66 static_assert( constepxr_test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10)), "" );
67 static_assert( constepxr_test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s)), "" );
68 static_assert( constepxr_test(s+5, 5, s+10), "" );
69 static_assert( constepxr_test(s+5, -5, s), "" );
70 }
71 #endif
72 }
73