libcxx/test/std/utilities/function.objects/range.cmp/equal_to.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::equal_to
  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 NotEqualityComparable {
  26   friend bool operator==(const NotEqualityComparable&, const NotEqualityComparable&);
  27   friend bool operator!=(const NotEqualityComparable&, const NotEqualityComparable&) = delete;
  28 };
  29
  30 static_assert(!std::is_invocable_v<std::ranges::equal_to, NotEqualityComparable, NotEqualityComparable>);
  31 static_assert(!std::is_invocable_v<std::ranges::equal_to, int, MoveOnly>);
  32 static_assert(std::is_invocable_v<std::ranges::equal_to, explicit_operators, explicit_operators>);
  33
  34 static_assert(requires { typename std::ranges::equal_to::is_transparent; });
  35
  36 constexpr bool test() {
  37   auto fn = std::ranges::equal_to();
  38
  39   assert(fn(MoveOnly(42), MoveOnly(42)));
  40
  41   ForwardingTestObject a;
  42   ForwardingTestObject b;
  43   assert(!fn(a, b));
  44   assert(fn(std::move(a), std::move(b)));
  45
  46   assert(!fn(1, 2));
  47   assert(!fn(2, 1));
  48   assert(fn(2, 2));
  49
  50   assert(!fn(2, 1L));
  51
  52   return true;
  53 }
  54
  55 int main(int, char**) {
  56
  57   test();
  58   static_assert(test());
  59
  60   // test total ordering of int* for equal_to<int*> and equal_to<void>.
  61   do_pointer_comparison_test(std::ranges::equal_to());
  62
  63   return 0;
  64 }