libcxx/test/std/utilities/optional/optional.comp_with_t/less_than.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
  10 // <optional>
  11
  12 // template <class T, class U> constexpr bool operator<(const optional<T>& x, const U& v);
  13 // template <class T, class U> constexpr bool operator<(const U& v, const optional<T>& x);
  14
  15 #include <optional>
  16
  17 #include "test_macros.h"
  18
  19 using std::optional;
  20
  21 struct X {
  22   int i_;
  23
  24   constexpr X(int i) : i_(i) {}
  25 };
  26
  27 constexpr bool operator<(const X& lhs, const X& rhs) { return lhs.i_ < rhs.i_; }
  28
  29 int main(int, char**) {
  30   {
  31     typedef X T;
  32     typedef optional<T> O;
  33
  34     constexpr T val(2);
  35     constexpr O o1;      // disengaged
  36     constexpr O o2{1};   // engaged
  37     constexpr O o3{val}; // engaged
  38
  39     static_assert((o1 < T(1)), "");
  40     static_assert(!(o2 < T(1)), ""); // equal
  41     static_assert(!(o3 < T(1)), "");
  42     static_assert((o2 < val), "");
  43     static_assert(!(o3 < val), ""); // equal
  44     static_assert((o3 < T(3)), "");
  45
  46     static_assert(!(T(1) < o1), "");
  47     static_assert(!(T(1) < o2), ""); // equal
  48     static_assert((T(1) < o3), "");
  49     static_assert(!(val < o2), "");
  50     static_assert(!(val < o3), ""); // equal
  51     static_assert(!(T(3) < o3), "");
  52   }
  53   {
  54     using O = optional<int>;
  55     constexpr O o1(42);
  56     static_assert(o1 < 101l, "");
  57     static_assert(!(42l < o1), "");
  58   }
  59   {
  60     using O = optional<const int>;
  61     constexpr O o1(42);
  62     static_assert(o1 < 101, "");
  63     static_assert(!(42 < o1), "");
  64   }
  65
  66   return 0;
  67 }