libcxx/test/std/utilities/format/format.tuple/parse.pass.cpp

   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, c++20
  10
  11 // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
  12
  13 // <format>
  14
  15 // template<class charT, formattable<charT>... Ts>
  16 //   struct formatter<pair-or-tuple<Ts...>, charT>
  17
  18 // template<class ParseContext>
  19 //   constexpr typename ParseContext::iterator
  20 //     parse(ParseContext& ctx);
  21
  22 // Note this tests the basics of this function. It's tested in more detail in
  23 // the format functions tests.
  24
  25 #include <cassert>
  26 #include <concepts>
  27 #include <format>
  28 #include <memory>
  29 #include <tuple>
  30 #include <utility>
  31
  32 #include "test_macros.h"
  33 #include "make_string.h"
  34
  35 #define SV(S) MAKE_STRING_VIEW(CharT, S)
  36
  37 template <class Arg, class StringViewT>
  38 constexpr void test(StringViewT fmt, std::size_t offset) {
  39   using CharT    = typename StringViewT::value_type;
  40   auto parse_ctx = std::basic_format_parse_context<CharT>(fmt);
  41   std::formatter<Arg, CharT> formatter;
  42   static_assert(std::semiregular<decltype(formatter)>);
  43
  44   std::same_as<typename StringViewT::iterator> auto it = formatter.parse(parse_ctx);
  45   // std::to_address works around LWG3989 and MSVC STL's iterator debugging mechanism.
  46   assert(std::to_address(it) == std::to_address(fmt.end()) - offset);
  47 }
  48
  49 template <class CharT, class Arg>
  50 constexpr void test() {
  51   test<Arg>(SV(""), 0);
  52   test<Arg>(SV("42"), 0);
  53
  54   test<Arg>(SV("}"), 1);
  55   test<Arg>(SV("42}"), 1);
  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 }