libcxx/test/std/utilities/meta/meta.logical/negation.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14
  10 // type_traits
  11
  12 // template<class B> struct negation;                        // C++17
  13 // template<class B>
  14 //   constexpr bool negation_v = negation<B>::value;         // C++17
  15
  16 #include <type_traits>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20
  21 struct True  { static constexpr bool value = true; };
  22 struct False { static constexpr bool value = false; };
  23
  24 int main(int, char**)
  25 {
  26     static_assert (!std::negation<std::true_type >::value, "" );
  27     static_assert ( std::negation<std::false_type>::value, "" );
  28
  29     static_assert (!std::negation_v<std::true_type >, "" );
  30     static_assert ( std::negation_v<std::false_type>, "" );
  31
  32     static_assert (!std::negation<True >::value, "" );
  33     static_assert ( std::negation<False>::value, "" );
  34
  35     static_assert (!std::negation_v<True >, "" );
  36     static_assert ( std::negation_v<False>, "" );
  37
  38     static_assert ( std::negation<std::negation<std::true_type >>::value, "" );
  39     static_assert (!std::negation<std::negation<std::false_type>>::value, "" );
  40
  41   return 0;
  42 }