libstdc++-v3/testsuite/20_util/variant/visit_neg.cc

   1 // Copyright (C) 2019-2022 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 <variant>
  22 #include <testsuite_hooks.h>
  23
  24 // { dg-error "same return type for all alternatives" "" { target *-*-* } 0 }
  25 // { dg-prune-output "in 'constexpr' expansion" }
  26
  27 void
  28 test01()
  29 {
  30   {
  31     struct Visitor
  32     {
  33       double operator()(double) {return 0.02;}
  34       void operator()(int) {}
  35     };
  36     std::variant<int, double> v;
  37     std::visit(Visitor(), v);
  38   }
  39 }
  40
  41 int
  42 main()
  43 {
  44   test01();
  45 }