93 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++1710 11// views::iota12 13#include <cassert>14#include <concepts>15#include <ranges>16#include <type_traits>17 18#include "test_macros.h"19#include "types.h"20 21template<class T, class U>22constexpr void testType(U u) {23 // Test that this generally does the right thing.24 // Test with only one argument.25 {26 assert(*std::views::iota(T(0)).begin() == T(0));27 }28 {29 const auto io = std::views::iota(T(10));30 assert(*io.begin() == T(10));31 }32 // Test with two arguments.33 {34 assert(*std::views::iota(T(0), u).begin() == T(0));35 }36 {37 const auto io = std::views::iota(T(10), u);38 assert(*io.begin() == T(10));39 }40 // Test that we return the correct type.41 {42 ASSERT_SAME_TYPE(decltype(std::views::iota(T(10))), std::ranges::iota_view<T>);43 ASSERT_SAME_TYPE(decltype(std::views::iota(T(10), u)), std::ranges::iota_view<T, U>);44 }45}46 47struct X {};48 49template <typename IntT>50concept CanDoubleWrap = requires(IntT i) { std::views::iota(std::views::iota(i)); };51 52constexpr bool test() {53 testType<SomeInt>(SomeInt(10));54 testType<SomeInt>(IntComparableWith(SomeInt(10)));55 testType<signed long>(IntComparableWith<signed long>(10));56 testType<unsigned long>(IntComparableWith<unsigned long>(10));57 testType<int>(IntComparableWith<int>(10));58 testType<int>(int(10));59 testType<unsigned>(unsigned(10));60 testType<unsigned>(IntComparableWith<unsigned>(10));61 testType<short>(short(10));62 testType<short>(IntComparableWith<short>(10));63 testType<unsigned short>(IntComparableWith<unsigned short>(10));64 65 {66 static_assert( std::is_invocable_v<decltype(std::views::iota), int>);67 static_assert(!std::is_invocable_v<decltype(std::views::iota), X>);68 static_assert( std::is_invocable_v<decltype(std::views::iota), int, int>);69 static_assert(!std::is_invocable_v<decltype(std::views::iota), int, X>);70 }71 {72 static_assert(std::same_as<decltype(std::views::iota), decltype(std::ranges::views::iota)>);73 }74 { // LWG4096: views::iota(views::iota(0)) should be rejected75 static_assert(!CanDoubleWrap<int>);76 static_assert(!CanDoubleWrap<SomeInt>);77 78 static_assert(!std::is_invocable_v<decltype(std::views::iota), decltype(std::views::iota(0))>);79 static_assert(!std::is_invocable_v<decltype(std::views::iota), decltype(std::views::iota(82))>);80 static_assert(!std::is_invocable_v<decltype(std::views::iota), decltype(std::views::iota(SomeInt(0)))>);81 static_assert(!std::is_invocable_v<decltype(std::views::iota), decltype(std::views::iota(SomeInt(94)))>);82 }83 84 return true;85}86 87int main(int, char**) {88 test();89 static_assert(test());90 91 return 0;92}93