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