libstdc++-v3/testsuite/21_strings/basic_string_view/requirements/constexpr_iter.cc

   1 // { dg-options "-std=gnu++2a" }
   2 // { dg-do compile { target c++2a } }
   3 //
   4 // Copyright (C) 2019 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <string_view>
  22 #include <array>
  23
  24 constexpr char
  25 test()
  26 {
  27   constexpr std::string_view hw("Hello, World!");
  28   static_assert('H' == *hw.begin());
  29   auto ch = hw[4];
  30   static_assert('W' == *(hw.cbegin() + 7));
  31
  32   std::array<int, hw.size()> a2{{0,0,0,0,0,0,0,0,0,0,0,0,0}};
  33   std::copy(hw.begin(), hw.end(), a2.begin());
  34
  35   return *(hw.cbegin() + 3);
  36 }
  37
  38 void
  39 run_test()
  40 {
  41   constexpr char ch = test();
  42 }