libcxx/test/std/utilities/meta/meta.help/integral_constant.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 // type_traits
  10
  11 // integral_constant
  12
  13 #include <type_traits>
  14 #include <cassert>
  15
  16 #include "test_macros.h"
  17
  18 int main(int, char**)
  19 {
  20     typedef std::integral_constant<int, 5> _5;
  21     static_assert(_5::value == 5, "");
  22     static_assert((std::is_same<_5::value_type, int>::value), "");
  23     static_assert((std::is_same<_5::type, _5>::value), "");
  24 #if TEST_STD_VER >= 11
  25     static_assert((_5() == 5), "");
  26 #endif
  27     assert(_5() == 5);
  28
  29
  30 #if TEST_STD_VER > 11
  31     static_assert ( _5{}() == 5, "" );
  32     static_assert ( std::true_type{}(), "" );
  33 #endif
  34
  35     static_assert(std::false_type::value == false, "");
  36     static_assert((std::is_same<std::false_type::value_type, bool>::value), "");
  37     static_assert((std::is_same<std::false_type::type, std::false_type>::value), "");
  38
  39     static_assert(std::true_type::value == true, "");
  40     static_assert((std::is_same<std::true_type::value_type, bool>::value), "");
  41     static_assert((std::is_same<std::true_type::type, std::true_type>::value), "");
  42
  43     std::false_type f1;
  44     std::false_type f2 = f1;
  45     assert(!f2);
  46
  47     std::true_type t1;
  48     std::true_type t2 = t1;
  49     assert(t2);
  50
  51   return 0;
  52 }