libcxx/test/std/utilities/optional/optional.relops/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 optional<U>& y);
  13
  14 #include <optional>
  15
  16 #include "test_macros.h"
  17
  18 using std::optional;
  19
  20 struct X {
  21   int i_;
  22
  23   constexpr X(int i) : i_(i) {}
  24 };
  25
  26 constexpr bool operator<(const X& lhs, const X& rhs) { return lhs.i_ < rhs.i_; }
  27
  28 int main(int, char**) {
  29   {
  30     typedef optional<X> O;
  31
  32     constexpr O o1;    // disengaged
  33     constexpr O o2;    // disengaged
  34     constexpr O o3{1}; // engaged
  35     constexpr O o4{2}; // engaged
  36     constexpr O o5{1}; // engaged
  37
  38     static_assert(!(o1 < o1), "");
  39     static_assert(!(o1 < o2), "");
  40     static_assert((o1 < o3), "");
  41     static_assert((o1 < o4), "");
  42     static_assert((o1 < o5), "");
  43
  44     static_assert(!(o2 < o1), "");
  45     static_assert(!(o2 < o2), "");
  46     static_assert((o2 < o3), "");
  47     static_assert((o2 < o4), "");
  48     static_assert((o2 < o5), "");
  49
  50     static_assert(!(o3 < o1), "");
  51     static_assert(!(o3 < o2), "");
  52     static_assert(!(o3 < o3), "");
  53     static_assert((o3 < o4), "");
  54     static_assert(!(o3 < o5), "");
  55
  56     static_assert(!(o4 < o1), "");
  57     static_assert(!(o4 < o2), "");
  58     static_assert(!(o4 < o3), "");
  59     static_assert(!(o4 < o4), "");
  60     static_assert(!(o4 < o5), "");
  61
  62     static_assert(!(o5 < o1), "");
  63     static_assert(!(o5 < o2), "");
  64     static_assert(!(o5 < o3), "");
  65     static_assert((o5 < o4), "");
  66     static_assert(!(o5 < o5), "");
  67   }
  68   {
  69     using O1 = optional<int>;
  70     using O2 = optional<long>;
  71     constexpr O1 o1(42);
  72     static_assert(o1 < O2(101), "");
  73     static_assert(!(O2(101) < o1), "");
  74   }
  75   {
  76     using O1 = optional<int>;
  77     using O2 = optional<const int>;
  78     constexpr O1 o1(42);
  79     static_assert(o1 < O2(101), "");
  80     static_assert(!(O2(101) < o1), "");
  81   }
  82
  83   return 0;
  84 }