ceph/src/boost/libs/variant/test/no_rvalue_to_nonconst_visitation.cpp

   1 // Copyright (c) 2017-2019 Antony Polukhin
   2 //
   3 // Distributed under the Boost Software License, Version 1.0. (See
   4 // accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include "boost/config.hpp"
   8 #include "boost/variant.hpp"
   9
  10 struct foo {};
  11
  12 struct some_user_provided_visitor_for_lvalues: boost::static_visitor<void> {
  13     void operator()(foo& ) const {}
  14     void operator()(int ) const {}
  15 };
  16
  17 int main() {
  18     boost::apply_visitor(
  19         some_user_provided_visitor_for_lvalues(),
  20         boost::variant<int, foo>(foo())
  21     );
  22
  23 #ifdef __GNUC__
  24 #   if __GNUC__ < 5 && __GNUC_MINOR__ < 8
  25 #       error This test does not pass on GCC < 4.8 because of the incomplete C++11 support
  26 #   endif
  27 #endif
  28
  29 #ifdef BOOST_MSVC
  30 #   error Temporaries/rvalues could bind to non-const lvalues on MSVC compilers
  31 #endif
  32 }