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 | // format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, |
19 | // const locale& loc, format-string<Args...> fmt, |
20 | // const Args&... args); |
21 | // template<class Out, class... Args> |
22 | // format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, |
23 | // const locale& loc, wformat-string<Args...> fmt, |
24 | // const Args&... args); |
25 | |
26 | #include <format> |
27 | #include <algorithm> |
28 | #include <cassert> |
29 | #include <list> |
30 | #include <locale> |
31 | #include <vector> |
32 | |
33 | #include "test_macros.h" |
34 | #include "format_tests.h" |
35 | #include "string_literal.h" |
36 | #include "test_format_string.h" |
37 | |
38 | auto 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::list<CharT> out; |
43 | std::format_to_n_result result = |
44 | std::format_to_n(std::back_inserter(out), 0, std::locale(), fmt, std::forward<Args>(args)...); |
45 | // To avoid signedness warnings make sure formatted_size uses the same type |
46 | // as result.size. |
47 | using diff_type = decltype(result.size); |
48 | diff_type formatted_size = std::formatted_size(std::locale(), fmt, std::forward<Args>(args)...); |
49 | |
50 | assert(result.size == formatted_size); |
51 | assert(out.empty()); |
52 | } |
53 | { |
54 | std::vector<CharT> out; |
55 | std::format_to_n_result result = |
56 | std::format_to_n(std::back_inserter(out), 5, std::locale(), fmt, std::forward<Args>(args)...); |
57 | using diff_type = decltype(result.size); |
58 | diff_type formatted_size = std::formatted_size(std::locale(), fmt, std::forward<Args>(args)...); |
59 | diff_type size = std::min<diff_type>(5, formatted_size); |
60 | |
61 | assert(result.size == formatted_size); |
62 | assert(std::equal(out.begin(), out.end(), expected.begin(), expected.begin() + size)); |
63 | } |
64 | { |
65 | std::basic_string<CharT> out; |
66 | std::format_to_n_result result = |
67 | std::format_to_n(std::back_inserter(out), 1000, std::locale(), fmt, std::forward<Args>(args)...); |
68 | using diff_type = decltype(result.size); |
69 | diff_type formatted_size = std::formatted_size(std::locale(), fmt, std::forward<Args>(args)...); |
70 | diff_type size = std::min<diff_type>(1000, formatted_size); |
71 | |
72 | assert(result.size == formatted_size); |
73 | assert(out == expected.substr(0, size)); |
74 | } |
75 | { |
76 | // Test the returned iterator. |
77 | std::basic_string<CharT> out(10, CharT(' ')); |
78 | std::format_to_n_result result = |
79 | std::format_to_n(out.begin(), 10, std::locale(), fmt, std::forward<Args>(args)...); |
80 | using diff_type = decltype(result.size); |
81 | diff_type formatted_size = std::formatted_size(std::locale(), fmt, std::forward<Args>(args)...); |
82 | diff_type size = std::min<diff_type>(10, formatted_size); |
83 | |
84 | assert(result.size == formatted_size); |
85 | assert(result.out == out.begin() + size); |
86 | assert(out.substr(0, size) == expected.substr(0, size)); |
87 | } |
88 | { |
89 | static_assert(std::is_signed_v<std::iter_difference_t<CharT*>>, |
90 | "If the difference type isn't negative the test will fail " |
91 | "due to using a large positive value." ); |
92 | CharT buffer[1] = {CharT(0)}; |
93 | std::format_to_n_result result = std::format_to_n(buffer, -1, std::locale(), fmt, std::forward<Args>(args)...); |
94 | using diff_type = decltype(result.size); |
95 | diff_type formatted_size = std::formatted_size(std::locale(), fmt, std::forward<Args>(args)...); |
96 | |
97 | assert(result.size == formatted_size); |
98 | assert(result.out == buffer); |
99 | assert(buffer[0] == CharT(0)); |
100 | } |
101 | }; |
102 | |
103 | auto test_exception = []<class CharT, class... Args>(std::string_view, std::basic_string_view<CharT>, Args&&...) { |
104 | // After P2216 most exceptions thrown by std::format_to_n become ill-formed. |
105 | // Therefore this tests does nothing. |
106 | // A basic ill-formed test is done in format_to_n.locale.verify.cpp |
107 | // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument. |
108 | }; |
109 | |
110 | int main(int, char**) { |
111 | format_tests<char, execution_modus::partial>(check: test, check_exception: test_exception); |
112 | |
113 | #ifndef TEST_HAS_NO_WIDE_CHARACTERS |
114 | format_tests_char_to_wchar_t(check: test); |
115 | format_tests<wchar_t, execution_modus::partial>(check: test, check_exception: test_exception); |
116 | #endif |
117 | |
118 | return 0; |
119 | } |
120 | |