xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/vformat_to.locale.pass.cpp (revision 6a54dfbfe534276d644d7f9c027f0deeb748dd53)
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>
18 //   Out vformat_to(Out out, const locale& loc, string_view fmt,
19 //                  format_args args);
20 // template<class Out>
21 //    Out vformat_to(Out out, const locale& loc, wstring_view fmt,
22 //                   wformat_args args);
23 
24 #include <format>
25 #include <algorithm>
26 #include <cassert>
27 #include <list>
28 #include <vector>
29 
30 #include "assert_macros.h"
31 #include "concat_macros.h"
32 #include "format_tests.h"
33 #include "string_literal.h"
34 
35 auto test = []<class CharT, class... Args>(
36                 std::basic_string_view<CharT> expected, std::basic_string_view<CharT> fmt, Args&&... args) constexpr {
37   {
38     std::basic_string<CharT> out(expected.size(), CharT(' '));
39     auto it = std::vformat_to(out.begin(), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
40     assert(it == out.end());
41     assert(out == expected);
42   }
43   {
44     std::list<CharT> out;
45     std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
46     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
47   }
48   {
49     std::vector<CharT> out;
50     std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
51     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
52   }
53   {
54     assert(expected.size() < 4096 && "Update the size of the buffer.");
55     CharT out[4096];
56     CharT* it = std::vformat_to(out, std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
57     assert(std::distance(out, it) == int(expected.size()));
58     // Convert to std::string since output contains '\0' for boolean tests.
59     assert(std::basic_string<CharT>(out, it) == expected);
60   }
61 };
62 
63 auto test_exception = []<class CharT, class... Args>([[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), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
77       }());
78 };
79 
80 int main(int, char**) {
81   format_tests<char, execution_modus::partial>(test, test_exception);
82 
83 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
84   format_tests_char_to_wchar_t(test);
85   format_tests<wchar_t, execution_modus::partial>(test, test_exception);
86 #endif
87 
88   return 0;
89 }
90