xref: /llvm-project/libcxx/test/std/utilities/format/format.tuple/parse.pass.cpp (revision 63ae5099b7339e87e6ce67fc7da63d26b8e7cb27)
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 
10 // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
11 
12 // <format>
13 
14 // template<class charT, formattable<charT>... Ts>
15 //   struct formatter<pair-or-tuple<Ts...>, charT>
16 
17 // template<class ParseContext>
18 //   constexpr typename ParseContext::iterator
19 //     parse(ParseContext& ctx);
20 
21 // Note this tests the basics of this function. It's tested in more detail in
22 // the format functions tests.
23 
24 #include <cassert>
25 #include <concepts>
26 #include <format>
27 #include <memory>
28 #include <tuple>
29 #include <utility>
30 
31 #include "test_macros.h"
32 #include "make_string.h"
33 
34 #define SV(S) MAKE_STRING_VIEW(CharT, S)
35 
36 template <class Arg, class StringViewT>
37 constexpr void test(StringViewT fmt, std::size_t offset) {
38   using CharT    = typename StringViewT::value_type;
39   auto parse_ctx = std::basic_format_parse_context<CharT>(fmt);
40   std::formatter<Arg, CharT> formatter;
41   static_assert(std::semiregular<decltype(formatter)>);
42 
43   std::same_as<typename StringViewT::iterator> auto it = formatter.parse(parse_ctx);
44   // std::to_address works around LWG3989 and MSVC STL's iterator debugging mechanism.
45   assert(std::to_address(it) == std::to_address(fmt.end()) - offset);
46 }
47 
48 template <class CharT, class Arg>
49 constexpr void test() {
50   test<Arg>(SV(""), 0);
51   test<Arg>(SV("42"), 0);
52 
53   test<Arg>(SV("}"), 1);
54   test<Arg>(SV("42}"), 1);
55 }
56 
57 template <class CharT>
58 constexpr void test() {
59   test<CharT, std::tuple<int>>();
60   test<CharT, std::tuple<int, CharT>>();
61   test<CharT, std::pair<int, CharT>>();
62   test<CharT, std::tuple<int, CharT, bool>>();
63 }
64 
65 constexpr bool test() {
66   test<char>();
67 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
68   test<wchar_t>();
69 #endif
70 
71   return true;
72 }
73 
74 int main(int, char**) {
75   test();
76   static_assert(test());
77 
78   return 0;
79 }
80