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// UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
11
12// XFAIL: availability-fp_to_chars-missing
13
14// <format>
15
16// template<class Out>
17// Out vformat_to(Out out, string_view fmt, format_args args);
18// template<class Out>
19// Out vformat_to(Out out, wstring_view fmt, wformat_args_t args);
20
21#include <format>
22#include <algorithm>
23#include <cassert>
24#include <list>
25#include <vector>
26
27#include "assert_macros.h"
28#include "concat_macros.h"
29#include "test_macros.h"
30#include "format_tests.h"
31#include "string_literal.h"
32
33auto test = []<class CharT, class... Args>(
34 std::basic_string_view<CharT> expected, std::basic_string_view<CharT> fmt, Args&&... args) constexpr {
35 {
36 std::basic_string<CharT> out(expected.size(), CharT(' '));
37 auto it = std::vformat_to(out.begin(), fmt, std::make_format_args<context_t<CharT>>(args...));
38 assert(it == out.end());
39 assert(out == expected);
40 }
41 {
42 std::list<CharT> out;
43 std::vformat_to(std::back_inserter(out), fmt, std::make_format_args<context_t<CharT>>(args...));
44 assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
45 }
46 {
47 std::vector<CharT> out;
48 std::vformat_to(std::back_inserter(out), fmt, std::make_format_args<context_t<CharT>>(args...));
49 assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
50 }
51 {
52 assert(expected.size() < 4096 && "Update the size of the buffer.");
53 CharT out[4096];
54 CharT* it = std::vformat_to(out, fmt, std::make_format_args<context_t<CharT>>(args...));
55 assert(std::distance(out, it) == int(expected.size()));
56 // Convert to std::string since output contains '\0' for boolean tests.
57 assert(std::basic_string<CharT>(out, it) == expected);
58 }
59};
60
61auto test_exception =
62 []<class CharT, class... Args>(
63 [[maybe_unused]] std::string_view what,
64 [[maybe_unused]] std::basic_string_view<CharT> fmt,
65 [[maybe_unused]] Args&&... args) {
66 TEST_VALIDATE_EXCEPTION(
67 std::format_error,
68 [&]([[maybe_unused]] const std::format_error& e) {
69 TEST_LIBCPP_REQUIRE(
70 e.what() == what,
71 TEST_WRITE_CONCATENATED(
72 "\nFormat string ", fmt, "\nExpected exception ", what, "\nActual exception ", e.what(), '\n'));
73 },
74 [&] {
75 std::basic_string<CharT> out;
76 std::vformat_to(std::back_inserter(out), fmt, std::make_format_args<context_t<CharT>>(args...));
77 }());
78 };
79
80int main(int, char**) {
81 format_tests<char, execution_modus::partial>(check: test, check_exception: test_exception);
82
83#ifndef TEST_HAS_NO_WIDE_CHARACTERS
84 format_tests_char_to_wchar_t(check: test);
85 format_tests<wchar_t, execution_modus::partial>(check: test, check_exception: test_exception);
86#endif
87
88 return 0;
89}
90

source code of libcxx/test/std/utilities/format/format.functions/vformat_to.pass.cpp