xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/format_to.locale.pass.cpp (revision 09e3a360581dc36d0820d3fb6da9bd7cfed87b5d)
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 
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::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 
68 auto 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 
75 int main(int, char**) {
76   format_tests<char, execution_modus::partial>(test, test_exception);
77 
78 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
79   format_tests_char_to_wchar_t(test);
80   format_tests<wchar_t, execution_modus::partial>(test, test_exception);
81 #endif
82 
83   return 0;
84 }
85