libcxx/test/std/algorithms/algorithms.results/min_max_result.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 // template <class I1, class I2>
  12 // struct min_max_result;
  13
  14 #include <algorithm>
  15 #include <cassert>
  16 #include <type_traits>
  17
  18 #include "MoveOnly.h"
  19
  20 struct A {
  21   explicit A(int);
  22 };
  23 // no implicit conversion
  24 static_assert(!std::is_constructible_v<std::ranges::min_max_result<A>, std::ranges::min_max_result<int>>);
  25
  26 struct B {
  27   B(int);
  28 };
  29 // implicit conversion
  30 static_assert(std::is_constructible_v<std::ranges::min_max_result<B>, std::ranges::min_max_result<int>>);
  31 static_assert(std::is_constructible_v<std::ranges::min_max_result<B>, std::ranges::min_max_result<int>&>);
  32 static_assert(std::is_constructible_v<std::ranges::min_max_result<B>, const std::ranges::min_max_result<int>>);
  33 static_assert(std::is_constructible_v<std::ranges::min_max_result<B>, const std::ranges::min_max_result<int>&>);
  34
  35 struct C {
  36   C(int&);
  37 };
  38 static_assert(!std::is_constructible_v<std::ranges::min_max_result<C>, std::ranges::min_max_result<int>&>);
  39
  40 // has to be convertible via const&
  41 static_assert(std::is_convertible_v<std::ranges::min_max_result<int>&, std::ranges::min_max_result<long>>);
  42 static_assert(std::is_convertible_v<const std::ranges::min_max_result<int>&, std::ranges::min_max_result<long>>);
  43 static_assert(std::is_convertible_v<std::ranges::min_max_result<int>&&, std::ranges::min_max_result<long>>);
  44 static_assert(std::is_convertible_v<const std::ranges::min_max_result<int>&&, std::ranges::min_max_result<long>>);
  45
  46 // should be move constructible
  47 static_assert(std::is_move_constructible_v<std::ranges::min_max_result<MoveOnly>>);
  48
  49 // should not be copy constructible
  50 static_assert(!std::is_copy_constructible_v<std::ranges::min_max_result<MoveOnly>>);
  51
  52 struct NotConvertible {};
  53 // conversions should not work if there is no conversion
  54 static_assert(!std::is_convertible_v<std::ranges::min_max_result<NotConvertible>, std::ranges::min_max_result<int>>);
  55
  56 template <class T>
  57 struct ConvertibleFrom {
  58   constexpr ConvertibleFrom(T c) : content{c} {}
  59   T content;
  60 };
  61
  62 constexpr bool test() {
  63   // Checks that conversion operations are correct.
  64   {
  65     std::ranges::min_max_result<double> res{10, 1};
  66     assert(res.min == 10);
  67     assert(res.max == 1);
  68     std::ranges::min_max_result<ConvertibleFrom<int>> res2 = res;
  69     assert(res2.min.content == 10);
  70     assert(res2.max.content == 1);
  71   }
  72
  73   // Checks that conversions are possible when one of the types is move-only.
  74   {
  75     std::ranges::min_max_result<MoveOnly> res{MoveOnly{}, MoveOnly{}};
  76     assert(res.min.get() == 1);
  77     assert(res.max.get() == 1);
  78     auto res2 = std::move(res);
  79     assert(res.min.get() == 0);
  80     assert(res.max.get() == 0);
  81     assert(res2.min.get() == 1);
  82     assert(res2.max.get() == 1);
  83   }
  84
  85   // Checks that structured bindings get the correct values.
  86   {
  87     auto [min, max] = std::ranges::min_max_result<int>{1, 2};
  88     assert(min == 1);
  89     assert(max == 2);
  90   }
  91
  92   return true;
  93 }
  94
  95 int main(int, char**) {
  96   test();
  97   static_assert(test());
  98
  99   return 0;
 100 }