libstdc++-v3/testsuite/std/ranges/subrange/lwg3286.cc

   1 // Copyright (C) 2020-2024 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-do run { target c++20 } }
  19
  20 #include <ranges>
  21 #include <testsuite_iterators.h>
  22 #include <testsuite_hooks.h>
  23
  24 using __gnu_test::test_input_range;
  25
  26 namespace ranges = std::ranges;
  27
  28 struct my_range
  29 {
  30   static inline int x[] = {1,2,3};
  31   static inline test_input_range<int> r{x};
  32
  33   bool called_begin = false;
  34
  35   auto
  36   begin()
  37   {
  38     called_begin = true;
  39     return r.begin();
  40   }
  41
  42   auto
  43   end()
  44   {
  45     return r.end();
  46   }
  47
  48   ranges::range_difference_t<decltype(r)>
  49   size()
  50   {
  51     VERIFY( !called_begin );
  52     return 3;
  53   }
  54 };
  55
  56 void
  57 test01()
  58 {
  59   my_range r;
  60   static_assert(!ranges::forward_range<my_range>);
  61   static_assert(ranges::sized_range<my_range>);
  62   ranges::subrange sr = r;
  63   VERIFY( ranges::size(sr) == 3 );
  64 }
  65
  66 int
  67 main()
  68 {
  69   test01();
  70 }