libcxx/test/std/iterators/predef.iterators/reverse.iterators/reverse.iter.nav/preincrement.pass.cpp

   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 // reverse_iterator
  12
  13 // reverse_iterator& operator++(); // constexpr in C++17
  14
  15 #include <iterator>
  16 #include <cassert>
  17
  18 #include "test_macros.h"
  19 #include "test_iterators.h"
  20
  21 template <class It>
  22 TEST_CONSTEXPR_CXX17 void test(It i, It x) {
  23     std::reverse_iterator<It> r(i);
  24     std::reverse_iterator<It>& rr = ++r;
  25     assert(r.base() == x);
  26     assert(&rr == &r);
  27 }
  28
  29 TEST_CONSTEXPR_CXX17 bool tests() {
  30     const char* s = "123";
  31     test(bidirectional_iterator<const char*>(s+1), bidirectional_iterator<const char*>(s));
  32     test(random_access_iterator<const char*>(s+1), random_access_iterator<const char*>(s));
  33     test(s+1, s);
  34     return true;
  35 }
  36
  37 int main(int, char**) {
  38     tests();
  39 #if TEST_STD_VER > 14
  40     static_assert(tests(), "");
  41 #endif
  42     return 0;
  43 }