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 // Check that ranges are marked [[nodiscard]] as a conforming extension 10 11 // UNSUPPORTED: c++03, c++11, c++14, c++17 12 13 // clang-format off 14 15 #include <ranges> 16 #include <functional> 17 #include <vector> 18 19 #include "test_macros.h" 20 21 void test() { 22 std::vector<int> range; 23 std::ranges::less_equal pred; 24 25 std::views::drop(pred); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 26 27 std::views::split(range, 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 28 std::views::split(1); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 29 30 std::views::take(range, 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 31 std::views::take(1); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 32 33 #if TEST_STD_VER >= 23 34 std::views::drop(std::views::repeat(1)); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 35 36 std::views::repeat(1); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 37 std::views::repeat(1, std::unreachable_sentinel); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 38 39 auto rvalue_view = std::views::as_rvalue(range); 40 std::views::as_rvalue(range); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 41 std::views::as_rvalue(rvalue_view); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 42 43 std::views::chunk_by(pred); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 44 std::views::chunk_by(range, pred); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 45 46 std::views::take(std::views::repeat(3), 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 47 std::views::take(std::views::repeat(3, std::unreachable_sentinel), 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 48 49 std::allocator<int> alloc; 50 51 std::ranges::to<std::vector<int>>(range); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 52 std::ranges::to<std::vector<int>>(range, alloc); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 53 std::ranges::to<std::vector>(range); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 54 std::ranges::to<std::vector>(range, alloc); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 55 range | std::ranges::to<std::vector<int>>(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 56 range | std::ranges::to<std::vector<int>>(alloc); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 57 range | std::ranges::to<std::vector>(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 58 range | std::ranges::to<std::vector>(alloc); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 59 #endif // TEST_STD_VER >= 23 60 } 61