libcxx/test/std/utilities/function.objects/comparisons/less.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 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
  10
  11 // <functional>
  12
  13 // less
  14
  15 #include <functional>
  16 #include <type_traits>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "pointer_comparison_test_helper.h"
  21
  22 int main(int, char**)
  23 {
  24     typedef std::less<int> F;
  25     const F f = F();
  26 #if TEST_STD_VER <= 17
  27     static_assert((std::is_same<int, F::first_argument_type>::value), "" );
  28     static_assert((std::is_same<int, F::second_argument_type>::value), "" );
  29     static_assert((std::is_same<bool, F::result_type>::value), "" );
  30 #endif
  31     assert(!f(36, 36));
  32     assert(!f(36, 6));
  33     assert(f(6, 36));
  34     {
  35         // test total ordering of int* for less<int*> and less<void>.
  36         do_pointer_comparison_test<std::less>();
  37     }
  38 #if TEST_STD_VER > 11
  39     typedef std::less<> F2;
  40     const F2 f2 = F2();
  41     assert(!f2(36, 36));
  42     assert(!f2(36, 6));
  43     assert( f2(6, 36));
  44     assert(!f2(36, 6.0));
  45     assert(!f2(36.0, 6));
  46     assert( f2(6, 36.0));
  47     assert( f2(6.0, 36));
  48
  49     constexpr bool foo = std::less<int> () (36, 36);
  50     static_assert ( !foo, "" );
  51
  52     constexpr bool bar = std::less<> () (36.0, 36);
  53     static_assert ( !bar, "" );
  54 #endif
  55
  56   return 0;
  57 }