libcxx/test/std/iterators/predef.iterators/reverse.iterators/reverse.iter.cons/assign.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 // template <class U>
  14 // reverse_iterator& operator=(const reverse_iterator<U>& u); // constexpr since C++17
  15
  16 #include <iterator>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "test_iterators.h"
  21
  22 template <class It, class U>
  23 TEST_CONSTEXPR_CXX17 void test(U u) {
  24     const std::reverse_iterator<U> r2(u);
  25     std::reverse_iterator<It> r1;
  26     std::reverse_iterator<It>& rr = r1 = r2;
  27     assert(base(r1.base()) == base(u));
  28     assert(&rr == &r1);
  29 }
  30
  31 struct Base { };
  32 struct Derived : Base { };
  33
  34 struct ToIter {
  35     typedef std::bidirectional_iterator_tag iterator_category;
  36     typedef char *pointer;
  37     typedef char &reference;
  38     typedef char value_type;
  39     typedef value_type difference_type;
  40
  41     explicit TEST_CONSTEXPR_CXX17 ToIter() : m_value(0) {}
  42     TEST_CONSTEXPR_CXX17 ToIter(const ToIter &src) : m_value(src.m_value) {}
  43     // Intentionally not defined, must not be called.
  44     ToIter(char *src);
  45     TEST_CONSTEXPR_CXX17 ToIter &operator=(char *src) {
  46         m_value = src;
  47         return *this;
  48     }
  49     TEST_CONSTEXPR_CXX17 ToIter &operator=(const ToIter &src) {
  50         m_value = src.m_value;
  51         return *this;
  52     }
  53     char *m_value;
  54
  55     reference operator*() const;
  56 };
  57
  58 TEST_CONSTEXPR_CXX17 bool tests() {
  59     Derived d;
  60     test<bidirectional_iterator<Base*> >(bidirectional_iterator<Derived*>(&d));
  61     test<random_access_iterator<const Base*> >(random_access_iterator<Derived*>(&d));
  62     test<Base*>(&d);
  63
  64     char c = '\0';
  65     char *fi = &c;
  66     const std::reverse_iterator<char *> rev_fi(fi);
  67     std::reverse_iterator<ToIter> rev_ti;
  68     rev_ti = rev_fi;
  69     assert(rev_ti.base().m_value == fi);
  70
  71     return true;
  72 }
  73
  74 int main(int, char**) {
  75     tests();
  76 #if TEST_STD_VER > 14
  77     static_assert(tests(), "");
  78 #endif
  79     return 0;
  80 }