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: no-localization
11// UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
12
13// XFAIL: availability-fp_to_chars-missing
14
15// <format>
16
17// template<class Out, class... Args>
18// Out format_to(Out out, const locale& loc,
19// format-string<Args...> fmt, const Args&... args);
20// template<class Out, class... Args>
21// Out format_to(Out out, const locale& loc,
22// wformat-string<Args...> fmt, const Args&... args);
23
24#include <format>
25#include <algorithm>
26#include <cassert>
27#include <iterator>
28#include <list>
29#include <locale>
30#include <vector>
31
32#include "test_macros.h"
33#include "format_tests.h"
34#include "string_literal.h"
35#include "test_format_string.h"
36#include "test_iterators.h"
37
38auto test =
39 []<class CharT, class... Args>(
40 std::basic_string_view<CharT> expected, test_format_string<CharT, Args...> fmt, Args&&... args) constexpr {
41 {
42 std::basic_string<CharT> out(expected.size(), CharT(' '));
43 auto it = std::format_to(out.begin(), std::locale(), fmt, std::forward<Args>(args)...);
44 assert(it == out.end());
45 assert(out == expected);
46 }
47 {
48 std::list<CharT> out;
49 std::format_to(std::back_inserter(out), std::locale(), fmt, std::forward<Args>(args)...);
50 assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
51 }
52 {
53 std::vector<CharT> out;
54 std::format_to(std::back_inserter(out), std::locale(), fmt, std::forward<Args>(args)...);
55 assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
56 }
57 {
58 assert(expected.size() < 4096 && "Update the size of the buffer.");
59 CharT out[4096];
60 cpp20_output_iterator<CharT*> it =
61 std::format_to(cpp20_output_iterator{out}, std::locale(), fmt, std::forward<Args>(args)...);
62 assert(std::distance(out, base(it)) == int(expected.size()));
63 // Convert to std::string since output contains '\0' for boolean tests.
64 assert(std::basic_string<CharT>(out, base(it)) == expected);
65 }
66 };
67
68auto test_exception = []<class CharT, class... Args>(std::string_view, std::basic_string_view<CharT>, Args&&...) {
69 // After P2216 most exceptions thrown by std::format_to become ill-formed.
70 // Therefore this tests does nothing.
71 // A basic ill-formed test is done in format_to.locale.verify.cpp
72 // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument.
73};
74
75int main(int, char**) {
76 format_tests<char, execution_modus::partial>(check: test, check_exception: test_exception);
77
78#ifndef TEST_HAS_NO_WIDE_CHARACTERS
79 format_tests_char_to_wchar_t(check: test);
80 format_tests<wchar_t, execution_modus::partial>(check: test, check_exception: test_exception);
81#endif
82
83 return 0;
84}
85

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