libstdc++-v3/testsuite/24_iterators/reverse_iterator/cust.cc

   1 // Copyright (C) 2019-2023 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do compile { target c++2a } }
  20
  21 #include <iterator>
  22 #include <testsuite_hooks.h>
  23
  24 // This test is an adaptation of 24_iterators/move_iterator/cust.cc.
  25
  26 constexpr bool
  27 test01()
  28 {
  29   struct X
  30   {
  31     constexpr X(int i) noexcept : i(i) { }
  32     constexpr X(X&& x) noexcept : i(x.i) { x.i = -1; }
  33     constexpr X& operator=(X&& x) noexcept { i = x.i; x.i = 0; return *this; }
  34     int i;
  35   };
  36
  37   X arr[] = { 1, 2 };
  38   std::reverse_iterator<X*> i(arr + 1), j(arr + 2);
  39   static_assert(noexcept(std::ranges::iter_swap(i, j)));
  40   std::ranges::iter_swap(i, j);
  41   VERIFY( arr[0].i == 2 );
  42   VERIFY( arr[1].i == 1 );
  43
  44   static_assert(noexcept(std::ranges::iter_move(i)));
  45   X x = std::ranges::iter_move(i);
  46   VERIFY( arr[0].i == -1 );
  47   VERIFY( x.i == 2 );
  48
  49   return true;
  50 }
  51
  52 static_assert(test01());