xref: /llvm-project/libcxx/test/std/utilities/format/format.tuple/parse.pass.cpp (revision 3d334df58742ff53fb00aa3caeb7eb5da3436348)
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, c++20
9 // UNSUPPORTED: libcpp-has-no-incomplete-format
10 
11 // TODO FMT Fix this test using GCC, it currently times out.
12 // UNSUPPORTED: gcc-12
13 
14 // <format>
15 
16 // template<class charT, formattable<charT>... Ts>
17 //   struct formatter<pair-or-tuple<Ts...>, charT>
18 
19 // template<class ParseContext>
20 //   constexpr typename ParseContext::iterator
21 //     parse(ParseContext& ctx);
22 
23 // Note this tests the basics of this function. It's tested in more detail in
24 // the format functions tests.
25 
26 #include <cassert>
27 #include <concepts>
28 #include <format>
29 #include <tuple>
30 #include <utility>
31 
32 #include "test_format_context.h"
33 #include "test_macros.h"
34 #include "make_string.h"
35 
36 #define SV(S) MAKE_STRING_VIEW(CharT, S)
37 
38 template <class Arg, class StringViewT>
39 constexpr void test(StringViewT fmt) {
40   using CharT    = typename StringViewT::value_type;
41   auto parse_ctx = std::basic_format_parse_context<CharT>(fmt);
42   std::formatter<Arg, CharT> formatter;
43   static_assert(std::semiregular<decltype(formatter)>);
44 
45   std::same_as<typename StringViewT::iterator> auto it = formatter.parse(parse_ctx);
46   assert(it == fmt.end() - (!fmt.empty() && fmt.back() == '}'));
47 }
48 
49 template <class CharT, class Arg>
50 constexpr void test() {
51   test<Arg>(SV(""));
52   test<Arg>(SV("42"));
53 
54   test<Arg>(SV("}"));
55   test<Arg>(SV("42}"));
56 }
57 
58 template <class CharT>
59 constexpr void test() {
60   test<CharT, std::tuple<int>>();
61   test<CharT, std::tuple<int, CharT>>();
62   test<CharT, std::pair<int, CharT>>();
63   test<CharT, std::tuple<int, CharT, bool>>();
64 }
65 
66 constexpr bool test() {
67   test<char>();
68 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
69   test<wchar_t>();
70 #endif
71 
72   return true;
73 }
74 
75 int main(int, char**) {
76   test();
77   static_assert(test());
78 
79   return 0;
80 }
81