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 // std::views::single 12 13 #include <ranges> 14 15 #include <cassert> 16 #include <concepts> 17 #include <utility> 18 #include "MoveOnly.h" 19 20 // Can't invoke without arguments. 21 static_assert(!std::is_invocable_v<decltype((std::views::single))>); 22 #if _LIBCPP_STD_VER >= 23 23 // Can invoke with a move-only type. 24 static_assert(std::is_invocable_v<decltype((std::views::single)), MoveOnly>); 25 #endif test()26constexpr bool test() { 27 // Lvalue. 28 { 29 int x = 42; 30 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(x); 31 assert(v.size() == 1); 32 assert(v.front() == x); 33 } 34 35 // Prvalue. 36 { 37 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(42); 38 assert(v.size() == 1); 39 assert(v.front() == 42); 40 } 41 42 // Const lvalue. 43 { 44 const int x = 42; 45 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(x); 46 assert(v.size() == 1); 47 assert(v.front() == x); 48 } 49 50 // Xvalue. 51 { 52 int x = 42; 53 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(std::move(x)); 54 assert(v.size() == 1); 55 assert(v.front() == x); 56 } 57 58 return true; 59 } 60 main(int,char **)61int main(int, char**) { 62 test(); 63 static_assert(test()); 64 65 return 0; 66 } 67