| //===----------------------------------------------------------------------===// |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME |
| |
| // XFAIL: availability-fp_to_chars-missing |
| |
| // <format> |
| |
| // template<class Out, class... Args> |
| // format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, |
| // format-string<Args...> fmt, const Args&... args); |
| // template<class Out, class... Args> |
| // format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, |
| // wformat-string<Args...> fmt, const Args&... args); |
| |
| #include <format> |
| #include <algorithm> |
| #include <cassert> |
| #include <iterator> |
| #include <list> |
| #include <vector> |
| |
| #include "test_macros.h" |
| #include "format_tests.h" |
| #include "string_literal.h" |
| #include "test_format_string.h" |
| |
| auto test = []<class CharT, class... Args>( |
| std::basic_string_view<CharT> expected, |
| test_format_string<CharT, Args...> fmt, |
| Args&&... args) constexpr { |
| { |
| std::list<CharT> out; |
| std::format_to_n_result result = std::format_to_n(std::back_inserter(out), 0, fmt, std::forward<Args>(args)...); |
| // To avoid signedness warnings make sure formatted_size uses the same type |
| // as result.size. |
| using diff_type = decltype(result.size); |
| diff_type formatted_size = std::formatted_size(fmt, std::forward<Args>(args)...); |
| |
| assert(result.size == formatted_size); |
| assert(out.empty()); |
| } |
| { |
| std::vector<CharT> out; |
| std::format_to_n_result result = std::format_to_n(std::back_inserter(out), 5, fmt, std::forward<Args>(args)...); |
| using diff_type = decltype(result.size); |
| diff_type formatted_size = std::formatted_size(fmt, std::forward<Args>(args)...); |
| diff_type size = std::min<diff_type>(5, formatted_size); |
| |
| assert(result.size == formatted_size); |
| assert(std::equal(out.begin(), out.end(), expected.begin(), expected.begin() + size)); |
| } |
| { |
| std::basic_string<CharT> out; |
| std::format_to_n_result result = std::format_to_n(std::back_inserter(out), 1000, fmt, std::forward<Args>(args)...); |
| using diff_type = decltype(result.size); |
| diff_type formatted_size = std::formatted_size(fmt, std::forward<Args>(args)...); |
| diff_type size = std::min<diff_type>(1000, formatted_size); |
| |
| assert(result.size == formatted_size); |
| assert(out == expected.substr(0, size)); |
| } |
| { |
| // Test the returned iterator. |
| std::basic_string<CharT> out(10, CharT(' ')); |
| std::format_to_n_result result = std::format_to_n(out.begin(), 10, fmt, std::forward<Args>(args)...); |
| using diff_type = decltype(result.size); |
| diff_type formatted_size = std::formatted_size(fmt, std::forward<Args>(args)...); |
| diff_type size = std::min<diff_type>(10, formatted_size); |
| |
| assert(result.size == formatted_size); |
| assert(result.out == out.begin() + size); |
| assert(out.substr(0, size) == expected.substr(0, size)); |
| } |
| { |
| static_assert(std::is_signed_v<std::iter_difference_t<CharT*>>, |
| "If the difference type isn't negative the test will fail " |
| "due to using a large positive value."); |
| CharT buffer[1] = {CharT(0)}; |
| std::format_to_n_result result = std::format_to_n(buffer, -1, fmt, std::forward<Args>(args)...); |
| using diff_type = decltype(result.size); |
| diff_type formatted_size = std::formatted_size(fmt, std::forward<Args>(args)...); |
| |
| assert(result.size == formatted_size); |
| assert(result.out == buffer); |
| assert(buffer[0] == CharT(0)); |
| } |
| }; |
| |
| auto test_exception = []<class CharT, class... Args>(std::string_view, std::basic_string_view<CharT>, Args&&...) { |
| // After P2216 most exceptions thrown by std::format_to_n become ill-formed. |
| // Therefore this tests does nothing. |
| // A basic ill-formed test is done in format_to_n.verify.cpp |
| // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument. |
| }; |
| |
| int main(int, char**) { |
| format_tests<char, execution_modus::partial>(test, test_exception); |
| |
| #ifndef TEST_HAS_NO_WIDE_CHARACTERS |
| format_tests_char_to_wchar_t(test); |
| format_tests<wchar_t, execution_modus::partial>(test, test_exception); |
| #endif |
| |
| return 0; |
| } |