libcxx/test/std/algorithms/algorithms.results/in_out_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 O1>
  12 // struct in_out_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::in_out_result<A, A>, std::ranges::in_out_result<int, int>>);
  25
  26 struct B {
  27   B(int);
  28 };
  29 // implicit conversion
  30 static_assert(std::is_constructible_v<std::ranges::in_out_result<B, B>, std::ranges::in_out_result<int, int>>);
  31 static_assert(std::is_constructible_v<std::ranges::in_out_result<B, B>, std::ranges::in_out_result<int, int>&>);
  32 static_assert(std::is_constructible_v<std::ranges::in_out_result<B, B>, const std::ranges::in_out_result<int, int>>);
  33 static_assert(std::is_constructible_v<std::ranges::in_out_result<B, B>, const std::ranges::in_out_result<int, int>&>);
  34
  35 struct C {
  36   C(int&);
  37 };
  38 static_assert(!std::is_constructible_v<std::ranges::in_out_result<C, C>, std::ranges::in_out_result<int, int>&>);
  39
  40 // has to be convertible via const&
  41 static_assert(std::is_convertible_v<std::ranges::in_out_result<int, int>&, std::ranges::in_out_result<long, long>>);
  42 static_assert(std::is_convertible_v<const std::ranges::in_out_result<int, int>&, std::ranges::in_out_result<long, long>>);
  43 static_assert(std::is_convertible_v<std::ranges::in_out_result<int, int>&&, std::ranges::in_out_result<long, long>>);
  44 static_assert(std::is_convertible_v<const std::ranges::in_out_result<int, int>&&, std::ranges::in_out_result<long, long>>);
  45
  46 // should be move constructible
  47 static_assert(std::is_move_constructible_v<std::ranges::in_out_result<MoveOnly, int>>);
  48 static_assert(std::is_move_constructible_v<std::ranges::in_out_result<int, MoveOnly>>);
  49
  50 struct NotConvertible {};
  51 // conversions should not work if there is no conversion
  52 static_assert(!std::is_convertible_v<std::ranges::in_out_result<NotConvertible, int>, std::ranges::in_out_result<int, NotConvertible>>);
  53 static_assert(!std::is_convertible_v<std::ranges::in_out_result<int, NotConvertible>, std::ranges::in_out_result<NotConvertible, int>>);
  54
  55 template <class T>
  56 struct ConvertibleFrom {
  57   constexpr ConvertibleFrom(T c) : content{c} {}
  58   T content;
  59 };
  60
  61 constexpr bool test() {
  62   // Checks that conversion operations are correct.
  63   {
  64     std::ranges::in_out_result<double, int> res{10, 1};
  65     assert(res.in == 10);
  66     assert(res.out == 1);
  67     std::ranges::in_out_result<ConvertibleFrom<double>, ConvertibleFrom<int>> res2 = res;
  68     assert(res2.in.content == 10);
  69     assert(res2.out.content == 1);
  70   }
  71
  72   // Checks that conversions are possible when one of the types is move-only.
  73   {
  74     std::ranges::in_out_result<MoveOnly, int> res{MoveOnly{}, 10};
  75     assert(res.in.get() == 1);
  76     assert(res.out == 10);
  77     auto res2 = std::move(res);
  78     assert(res.in.get() == 0);
  79     assert(res.out == 10);
  80     assert(res2.in.get() == 1);
  81     assert(res2.out == 10);
  82   }
  83
  84   // Checks that structured bindings get the correct values.
  85   {
  86     auto [min, max] = std::ranges::in_out_result<int, int>{1, 2};
  87     assert(min == 1);
  88     assert(max == 2);
  89   }
  90
  91   return true;
  92 }
  93
  94 int main(int, char**) {
  95   test();
  96   static_assert(test());
  97
  98   return 0;
  99 }