libcxx/test/std/utilities/function.objects/range.cmp/greater.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, c++17
  10
  11 // <functional>
  12
  13 // ranges::greater
  14
  15 #include <cassert>
  16 #include <functional>
  17 #include <type_traits>
  18 #include <utility>
  19
  20 #include "test_macros.h"
  21 #include "compare_types.h"
  22 #include "MoveOnly.h"
  23 #include "pointer_comparison_test_helper.h"
  24
  25 struct NotTotallyOrdered {
  26   friend bool operator<(const NotTotallyOrdered&, const NotTotallyOrdered&);
  27 };
  28
  29 static_assert(!std::is_invocable_v<std::ranges::greater, NotTotallyOrdered, NotTotallyOrdered>);
  30 static_assert(!std::is_invocable_v<std::ranges::greater, int, MoveOnly>);
  31 static_assert(std::is_invocable_v<std::ranges::greater, explicit_operators, explicit_operators>);
  32
  33 static_assert(requires { typename std::ranges::greater::is_transparent; });
  34
  35 constexpr bool test() {
  36   auto fn = std::ranges::greater();
  37
  38   assert(fn(MoveOnly(42), MoveOnly(41)));
  39
  40   ForwardingTestObject a;
  41   ForwardingTestObject b;
  42   assert(!fn(a, b));
  43   assert(fn(std::move(a), std::move(b)));
  44
  45   assert(!fn(2, 2));
  46   assert(!fn(1, 2));
  47   assert(fn(2, 1));
  48
  49   assert(fn(2, 1L));
  50
  51   return true;
  52 }
  53
  54 int main(int, char**) {
  55
  56   test();
  57   static_assert(test());
  58
  59   // test total ordering of int* for greater<int*> and greater<void>.
  60   do_pointer_comparison_test(std::ranges::greater());
  61
  62   return 0;
  63 }