libcxx/test/std/utilities/optional/optional.relops/compare.three_way.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 // <optional>
  12
  13 // [optional.relops], relational operators
  14
  15 // template<class T, three_way_comparable_with<T> U>
  16 //   constexpr compare_three_way_result_t<T, U>
  17 //     operator<=>(const optional<T>&, const optional<U>&);
  18
  19 #include <cassert>
  20 #include <compare>
  21 #include <optional>
  22
  23 #include "test_comparisons.h"
  24
  25 constexpr bool test() {
  26   {
  27     std::optional<int> op1;
  28     std::optional<int> op2;
  29
  30     assert((op1 <=> op2) == std::strong_ordering::equal);
  31     assert(testOrder(op1, op2, std::strong_ordering::equal));
  32   }
  33   {
  34     std::optional<int> op1{3};
  35     std::optional<int> op2{3};
  36     assert((op1 <=> op1) == std::strong_ordering::equal);
  37     assert(testOrder(op1, op1, std::strong_ordering::equal));
  38     assert((op1 <=> op2) == std::strong_ordering::equal);
  39     assert(testOrder(op1, op2, std::strong_ordering::equal));
  40     assert((op2 <=> op1) == std::strong_ordering::equal);
  41     assert(testOrder(op2, op1, std::strong_ordering::equal));
  42   }
  43   {
  44     std::optional<int> op;
  45     std::optional<int> op1{2};
  46     std::optional<int> op2{3};
  47     assert((op <=> op2) == std::strong_ordering::less);
  48     assert(testOrder(op, op2, std::strong_ordering::less));
  49     assert((op1 <=> op2) == std::strong_ordering::less);
  50     assert(testOrder(op1, op2, std::strong_ordering::less));
  51   }
  52   {
  53     std::optional<int> op;
  54     std::optional<int> op1{3};
  55     std::optional<int> op2{2};
  56     assert((op1 <=> op) == std::strong_ordering::greater);
  57     assert(testOrder(op1, op, std::strong_ordering::greater));
  58     assert((op1 <=> op2) == std::strong_ordering::greater);
  59     assert(testOrder(op1, op2, std::strong_ordering::greater));
  60   }
  61
  62   return true;
  63 }
  64
  65 int main(int, char**) {
  66   assert(test());
  67   static_assert(test());
  68   return 0;
  69 }