libstdc++-v3/testsuite/20_util/tuple/53648.cc

   1 // { dg-options "-std=gnu++0x" }
   2 // { dg-do compile }
   3
   4 // Copyright (C) 2012-2014 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 // libstdc++/53648
  22
  23 #include <tuple>
  24 #include <type_traits>
  25
  26 using std::tuple;
  27
  28 struct A { };
  29
  30 template class tuple<tuple<>>;
  31 template class tuple<tuple<tuple<>>>;
  32 template class tuple<A, tuple<A, tuple<A, tuple<A>>>>;
  33 template class tuple<tuple<tuple<A, A>, A>, A>;
  34
  35 // Verify the following QoI properties are preserved
  36
  37 static_assert( std::is_empty<tuple<>>::value, "tuple<> is empty" );
  38
  39 static_assert( std::is_empty<tuple<tuple<>>>::value,
  40                "tuple<tuple<>> is empty" );
  41
  42 static_assert( sizeof(tuple<char, tuple<>>) == sizeof(char),
  43                "tuple<> is eligible for EBO" );
  44