Home | History | Annotate | Download | only in iterator.operations 
      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 // template <InputIterator Iter>
     13 //   Iter next(Iter x, Iter::difference_type n = 1);
     14 
     15 // LWG #2353 relaxed the requirement on next from ForwardIterator to InputIterator
     16 
     17 #include <iterator>
     18 #include <cassert>
     19 
     20 #include "test_iterators.h"
     21 
     22 template <class It>
     23 void
     24 test(It i, typename std::iterator_traits<It>::difference_type n, It x)
     25 {
     26     assert(std::next(i, n) == x);
     27 
     28     It (*next)(It, typename std::iterator_traits<It>::difference_type) = std::next;
     29     assert(next(i, n) == x);
     30 }
     31 
     32 template <class It>
     33 void
     34 test(It i, It x)
     35 {
     36     assert(std::next(i) == x);
     37 }
     38 
     39 #if TEST_STD_VER > 14
     40 template <class It>
     41 constexpr bool
     42 constexpr_test(It i, typename std::iterator_traits<It>::difference_type n, It x)
     43 {
     44     return std::next(i, n) == x;
     45 }
     46 
     47 template <class It>
     48 constexpr bool
     49 constexpr_test(It i, It x)
     50 {
     51     return std::next(i) == x;
     52 }
     53 #endif
     54 
     55 int main()
     56 {
     57     {
     58     const char* s = "1234567890";
     59     test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10));
     60     test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10));
     61     test(bidirectional_iterator<const char*>(s), 10, bidirectional_iterator<const char*>(s+10));
     62     test(random_access_iterator<const char*>(s), 10, random_access_iterator<const char*>(s+10));
     63     test(s, 10, s+10);
     64 
     65     test(input_iterator<const char*>(s), input_iterator<const char*>(s+1));
     66     test(forward_iterator<const char*>(s), forward_iterator<const char*>(s+1));
     67     test(bidirectional_iterator<const char*>(s), bidirectional_iterator<const char*>(s+1));
     68     test(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s+1));
     69     test(s, s+1);
     70     }
     71 #if TEST_STD_VER > 14
     72     {
     73     constexpr const char* s = "1234567890";
     74     static_assert( constexpr_test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10)), "" );
     75     static_assert( constexpr_test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10)), "" );
     76     static_assert( constexpr_test(bidirectional_iterator<const char*>(s), 10, bidirectional_iterator<const char*>(s+10)), "" );
     77     static_assert( constexpr_test(random_access_iterator<const char*>(s), 10, random_access_iterator<const char*>(s+10)), "" );
     78     static_assert( constexpr_test(s, 10, s+10), "" );
     79 
     80     static_assert( constexpr_test(input_iterator<const char*>(s), input_iterator<const char*>(s+1)), "" );
     81     static_assert( constexpr_test(forward_iterator<const char*>(s), forward_iterator<const char*>(s+1)), "" );
     82     static_assert( constexpr_test(bidirectional_iterator<const char*>(s), bidirectional_iterator<const char*>(s+1)), "" );
     83     static_assert( constexpr_test(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s+1)), "" );
     84     static_assert( constexpr_test(s, s+1), "" );
     85     }
     86 #endif
     87 }
     88