1 //===----------------------------------------------------------------------===//
2 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
3 // See https://llvm.org/LICENSE.txt for license information.
4 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
5 //
6 //===----------------------------------------------------------------------===//
7 
8 // UNSUPPORTED: c++03, c++11, c++14, c++17
9 // UNSUPPORTED: no-localization
10 // UNSUPPORTED: libcpp-has-no-incomplete-format
11 // TODO FMT Evaluate gcc-12 status
12 // UNSUPPORTED: gcc-12
13 // TODO FMT Investigate AppleClang ICE
14 // UNSUPPORTED: apple-clang-13
15 
16 // <format>
17 
18 // template<class Out>
19 //   Out vformat_to(Out out, const locale& loc, string_view fmt,
20 //                  format_args args);
21 // template<class Out>
22 //    Out vformat_to(Out out, const locale& loc, wstring_view fmt,
23 //                   wformat_args args);
24 
25 #include <format>
26 #include <algorithm>
27 #include <cassert>
28 #include <list>
29 #include <vector>
30 
31 #include "test_macros.h"
32 #include "format_tests.h"
33 #include "string_literal.h"
34 
35 auto test = []<string_literal fmt, class CharT, class... Args>(std::basic_string_view<CharT> expected,
36                                                                const Args&... args) constexpr {
37   {
38     std::basic_string<CharT> out(expected.size(), CharT(' '));
39     auto it = std::vformat_to(out.begin(), std::locale(), fmt.template sv<CharT>(),
40                               std::make_format_args<context_t<CharT>>(args...));
41     assert(it == out.end());
42     assert(out == expected);
43   }
44   {
45     std::list<CharT> out;
46     std::vformat_to(std::back_inserter(out), std::locale(), fmt.template sv<CharT>(),
47                     std::make_format_args<context_t<CharT>>(args...));
48     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
49   }
50   {
51     std::vector<CharT> out;
52     std::vformat_to(std::back_inserter(out), std::locale(), fmt.template sv<CharT>(),
53                     std::make_format_args<context_t<CharT>>(args...));
54     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
55   }
56   {
57     assert(expected.size() < 4096 && "Update the size of the buffer.");
58     CharT out[4096];
59     CharT* it =
60         std::vformat_to(out, std::locale(), fmt.template sv<CharT>(), std::make_format_args<context_t<CharT>>(args...));
61     assert(std::distance(out, it) == int(expected.size()));
62     // Convert to std::string since output contains '\0' for boolean tests.
63     assert(std::basic_string<CharT>(out, it) == expected);
64   }
65 };
66 
67 auto test_exception = []<class CharT, class... Args>(std::string_view what, std::basic_string_view<CharT> fmt,
68                                                      const Args&... args) {
69 #ifndef TEST_HAS_NO_EXCEPTIONS
70   try {
71     std::basic_string<CharT> out;
72     std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
73     assert(false);
74   } catch ([[maybe_unused]] const std::format_error& e) {
75     LIBCPP_ASSERT(e.what() == what);
76     return;
77   }
78   assert(false);
79 #endif
80   (void)what;
81   (void)fmt;
82   (void)sizeof...(args);
83 };
84 
main(int,char **)85 int main(int, char**) {
86   format_tests<char>(test, test_exception);
87 
88 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
89   format_tests_char_to_wchar_t(test);
90   format_tests<wchar_t>(test, test_exception);
91 #endif
92 
93   return 0;
94 }
95