libstdc++-v3/testsuite/20_util/aligned_union/1.cc

   1 // { dg-options " -std=gnu++11 " }
   2 // { dg-do compile }
   3
   4 // 2014-04-16 Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
   5
   6 // Copyright (C) 2014 Free Software Foundation, Inc.
   7 //
   8 // This file is part of the GNU ISO C++ Library.  This library is free
   9 // software; you can redistribute it and/or modify it under the terms
  10 // of the GNU General Public License as published by the Free Software
  11 // Foundation; either version 3, or (at your option) any later
  12 // version.
  13
  14 // This library is distributed in the hope that it will be useful, but
  15 // WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 // General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License
  20 // along with this library; see the file COPYING3.  If not see
  21 // <http://www.gnu.org/licenses/>.
  22
  23 // C++11 [meta.trans.other] 20.9.7.6: aligned_union
  24
  25 #include <type_traits>
  26 #include <testsuite_tr1.h>
  27
  28 struct MSAlignType { } __attribute__((__aligned__));
  29
  30 template<typename...T>
  31   struct mymax
  32   {
  33     static const std::size_t alignment = 0;
  34     static const std::size_t size = 0;
  35   };
  36
  37 template<typename L,  typename...T>
  38   struct mymax<L, T...>
  39   {
  40     static const std::size_t alignment = alignof(L) > mymax<T...>::alignment
  41       ? alignof(L) : mymax<T...>::alignment;
  42     static const std::size_t size = sizeof(L) > mymax<T...>::size
  43       ? sizeof(L) : mymax<T...>::size;
  44   };
  45
  46 void test01()
  47 {
  48   using std::aligned_union;
  49   using std::alignment_of;
  50   using std::size_t;
  51   using namespace __gnu_test;
  52
  53   const size_t max_a = mymax<char, short, int, double, int[4],
  54                              ClassType, MSAlignType>::alignment;
  55   const size_t max_s = mymax<char, short, int, double, int[4],
  56                              ClassType, MSAlignType>::size;
  57
  58   typedef aligned_union<0, char, short, int, double, int[4],
  59                         ClassType, MSAlignType> au_type;
  60   static_assert(au_type::alignment_value == max_a, "Alignment value");
  61   static_assert(sizeof(au_type::type) >= max_s, "Storage size");
  62
  63   typedef aligned_union<max_s+100, char, short, int, double, int[4],
  64                         ClassType, MSAlignType> au_type2;
  65   static_assert(sizeof(au_type2::type) >= max_s+100,
  66                 "Storage size (at least len)");
  67 }
  68
  69 int main()
  70 {
  71   test01();
  72 }