libstdc++-v3/testsuite/21_strings/basic_string_view/operations/copy/char/constexpr.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 compile { target c++20 } }
  19 // { dg-add-options no_pch }
  20
  21 #include <string_view>
  22
  23 #ifndef __cpp_lib_constexpr_string_view
  24 # error "Feature test macro for constexpr copy is missing in <string_view>"
  25 #elif __cpp_lib_constexpr_string_view < 201811L
  26 # error "Feature test macro for constexpr copy has wrong value in <string_view>"
  27 #endif
  28
  29 constexpr bool
  30 test01()
  31 {
  32   std::string_view s = "Everything changes and nothing stands still.";
  33   char buf[7]{};
  34   auto n = s.copy(buf, 7, 11);
  35   return std::string_view(buf, n) == "changes";
  36 }
  37
  38 static_assert( test01() );