xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/format.pass.cpp (revision 49d4fee9940f5e1273cc0ae30da82df9c1437706)
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: libcpp-has-no-incomplete-format
10 // TODO FMT Evaluate gcc-12 status
11 // UNSUPPORTED: gcc-12
12 
13 // Note this formatter shows additional information when tests are failing.
14 // This aids the development. Since other formatters fail in the same fashion
15 // they don't have this additional output.
16 
17 // <format>
18 
19 // template<class... Args>
20 //   string format(format-string<Args...> fmt, const Args&... args);
21 // template<class... Args>
22 //   wstring format(wformat-string<Args...> fmt, const Args&... args);
23 
24 #include <format>
25 #include <cassert>
26 #include <vector>
27 
28 #include "test_macros.h"
29 #include "format_tests.h"
30 #include "string_literal.h"
31 #include "test_format_string.h"
32 
33 #ifndef TEST_HAS_NO_LOCALIZATION
34 #  include <iostream>
35 #  include <type_traits>
36 #endif
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       std::basic_string<CharT> out = std::format(fmt, std::forward<Args>(args)...);
42 #ifndef TEST_HAS_NO_LOCALIZATION
43       if constexpr (std::same_as<CharT, char>)
44         if (out != expected)
45           std::cerr << "\nFormat string   " << fmt.get() << "\nExpected output " << expected << "\nActual output   "
46                     << out << '\n';
47 #endif
48       assert(out == expected);
49     };
50 
51 auto test_exception = []<class CharT, class... Args>(std::string_view, std::basic_string_view<CharT>, Args&&...) {
52   // After P2216 most exceptions thrown by std::format become ill-formed.
53   // Therefore this tests does nothing.
54   // A basic ill-formed test is done in format.verify.cpp
55   // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument.
56 };
57 
58 int main(int, char**) {
59   format_tests<char, execution_modus::full>(test, test_exception);
60 
61 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
62   format_tests_char_to_wchar_t(test);
63   format_tests<wchar_t, execution_modus::full>(test, test_exception);
64 #endif
65 
66   return 0;
67 }
68