112 lines · 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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++17, c++2010 11// std::views::as_rvalue12 13#include <cassert>14#include <functional>15#include <ranges>16#include <vector>17 18#include "test_iterators.h"19 20struct DefaultConstructibleView : std::ranges::view_base {21 int i_;22 int* begin();23 int* end();24};25 26struct RValueView : std::ranges::view_base {};27 28template <class View, class T>29concept HasPipe = requires(View&& view, T&& t) {30 { std::forward<View>(view) | std::forward<T>(t) };31};32 33struct NoView {};34static_assert(std::is_invocable_v<decltype(std::views::as_rvalue), DefaultConstructibleView>);35static_assert(!std::is_invocable_v<decltype(std::views::as_rvalue)>);36static_assert(!std::is_invocable_v<decltype(std::views::as_rvalue), NoView>);37static_assert(HasPipe<DefaultConstructibleView&, decltype(std::views::as_rvalue)>);38static_assert(HasPipe<int (&)[10], decltype(std::views::as_rvalue)>);39static_assert(!HasPipe<int (&&)[10], decltype(std::views::as_rvalue)>);40static_assert(!HasPipe<NoView, decltype(std::views::as_rvalue)>);41static_assert(std::is_same_v<decltype(std::views::as_rvalue), decltype(std::ranges::views::as_rvalue)>);42 43struct move_iterator_range {44 constexpr std::move_iterator<int*> begin() const { return {}; }45 constexpr std::move_iterator<int*> end() const { return {}; }46};47 48static_assert(!std::ranges::view<move_iterator_range>);49static_assert(std::ranges::range<move_iterator_range>);50 51// LWG4083: views::as_rvalue should reject non-input ranges52struct I {53 int operator*();54 using difference_type = int;55 I& operator++();56 void operator++(int);57};58static_assert(!std::is_invocable_v<decltype(std::views::as_rvalue),59 decltype(std::ranges::subrange{I{}, std::unreachable_sentinel})>);60static_assert(61 !HasPipe<decltype(std::ranges::subrange{I{}, std::unreachable_sentinel}), decltype(std::views::as_rvalue)>);62 63constexpr bool test() {64 { // view | views::as_rvalue65 DefaultConstructibleView v{{}, 3};66 std::same_as<std::ranges::as_rvalue_view<DefaultConstructibleView>> decltype(auto) view = v | std::views::as_rvalue;67 assert(view.base().i_ == 3);68 }69 70 { // adaptor | views::as_rvalue71 DefaultConstructibleView v{{}, 3};72 const auto partial = std::views::transform(std::identity{}) | std::views::as_rvalue;73 std::same_as<std::ranges::as_rvalue_view<74 std::ranges::transform_view<DefaultConstructibleView, std::identity>>> decltype(auto) view = partial(v);75 assert(view.base().base().i_ == 3);76 }77 78 { // views::as_rvalue | adaptor79 DefaultConstructibleView v{{}, 3};80 const auto partial = std::views::as_rvalue | std::views::transform(std::identity{});81 std::same_as<std::ranges::transform_view<std::ranges::as_rvalue_view<DefaultConstructibleView>,82 std::identity>> decltype(auto) view = partial(v);83 assert(view.base().base().i_ == 3);84 }85 86 { // rvalue-view | views::as_rvalue87 int a[4] = {1, 2, 3, 4};88 std::ranges::subrange range(rvalue_iterator{a}, rvalue_iterator{a + 4});89 [[maybe_unused]] std::same_as<std::ranges::subrange<rvalue_iterator<int>>> decltype(auto) rval_range =90 range | std::views::as_rvalue;91 }92 93 { // range | views::as_rvalue94 [[maybe_unused]] std::same_as<std::ranges::as_rvalue_view<std::views::all_t<std::vector<int>>>> decltype(auto)95 view = std::vector<int>{} | std::views::as_rvalue;96 }97 98 { // rvalue-range | views::as_rvalue99 [[maybe_unused]] std::same_as<std::views::all_t<move_iterator_range>> decltype(auto) view =100 move_iterator_range{} | std::views::as_rvalue;101 }102 103 return true;104}105 106int main(int, char**) {107 test();108 static_assert(test());109 110 return 0;111}112