libstdc++-v3/testsuite/27_io/basic_ostream/inserters_other/wchar_t/6.cc

   1 // { dg-do run { target c++11 } }
   2
   3 // Copyright (C) 2016-2020 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 27.6.2.5.3 basic_ostream manipulator inserters
  21
  22 #include <sstream>
  23
  24 struct X {};
  25 std::wostream& operator<<(std::wostream&, const X&) = delete;
  26
  27 struct Y {};
  28 std::wostream& operator<<(std::wostream& os, const Y&) {return os;}
  29 std::wostream& operator<<(std::wostream&& os, const Y&) {return os;}
  30
  31 struct Z{};
  32
  33 template <class T>
  34 auto f(T&&) -> decltype(void(std::declval<std::wostream&>()
  35                              << std::declval<T&&>()),
  36                         std::true_type());
  37
  38 std::false_type f(...);
  39
  40 template <class T>
  41 auto g(T&&) -> decltype(void(std::declval<std::wostream&&>()
  42                              << std::declval<T&&>()),
  43                         std::true_type());
  44
  45 std::false_type g(...);
  46
  47 void test01()
  48 {
  49   Y y;
  50   std::wostringstream os;
  51   os << y;
  52   os << Y();
  53   std::wostringstream() << y;
  54   std::wostringstream() << Y();
  55   static_assert(!std::__is_insertable<std::wostream&, X&>::value, "");
  56   static_assert(!std::__is_insertable<std::wostream&&, X&>::value, "");
  57   static_assert(!std::__is_insertable<std::wostream&, X&&>::value, "");
  58   static_assert(!std::__is_insertable<std::wostream&&, X&&>::value, "");
  59   static_assert(std::__is_insertable<std::wostream&, Y&>::value, "");
  60   static_assert(std::__is_insertable<std::wostream&&, Y&&>::value, "");
  61   static_assert(std::__is_insertable<std::wostream&, Y&>::value, "");
  62   static_assert(std::__is_insertable<std::wostream&&, Y&&>::value, "");
  63   static_assert(!std::__is_insertable<std::wostream&, Z&>::value, "");
  64   static_assert(!std::__is_insertable<std::wostream&&, Z&>::value, "");
  65   static_assert(!std::__is_insertable<std::wostream&, Z&&>::value, "");
  66   static_assert(!std::__is_insertable<std::wostream&&, Z&&>::value, "");
  67   static_assert(std::is_same<decltype(f(std::declval<X&>())),
  68                 std::false_type>::value, "");
  69   static_assert(std::is_same<decltype(f(std::declval<X&&>())),
  70                 std::false_type>::value, "");
  71   static_assert(std::is_same<decltype(f(std::declval<Y&>())),
  72                 std::true_type>::value, "");
  73   static_assert(std::is_same<decltype(f(std::declval<Y&&>())),
  74                 std::true_type>::value, "");
  75   static_assert(std::is_same<decltype(f(std::declval<Z&>())),
  76                 std::false_type>::value, "");
  77   static_assert(std::is_same<decltype(f(std::declval<Z&&>())),
  78                 std::false_type>::value, "");
  79   static_assert(std::is_same<decltype(g(std::declval<X&>())),
  80                 std::false_type>::value, "");
  81   static_assert(std::is_same<decltype(g(std::declval<X&&>())),
  82                 std::false_type>::value, "");
  83   static_assert(std::is_same<decltype(g(std::declval<Y&>())),
  84                 std::true_type>::value, "");
  85   static_assert(std::is_same<decltype(g(std::declval<Y&&>())),
  86                 std::true_type>::value, "");
  87   static_assert(std::is_same<decltype(g(std::declval<Z&>())),
  88                 std::false_type>::value, "");
  89   static_assert(std::is_same<decltype(g(std::declval<Z&&>())),
  90                 std::false_type>::value, "");
  91 }
  92
  93 int main()
  94 {
  95   test01();
  96 }