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

   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 <tuple>
  28 #include <utility>
  29
  30 #include "test_format_context.h"
  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   assert(it == fmt.end() - offset);
  45 }
  46
  47 template <class CharT, class Arg>
  48 constexpr void test() {
  49   test<Arg>(SV(""), 0);
  50   test<Arg>(SV("42"), 0);
  51
  52   test<Arg>(SV("}"), 1);
  53   test<Arg>(SV("42}"), 1);
  54 }
  55
  56 template <class CharT>
  57 constexpr void test() {
  58   test<CharT, std::tuple<int>>();
  59   test<CharT, std::tuple<int, CharT>>();
  60   test<CharT, std::pair<int, CharT>>();
  61   test<CharT, std::tuple<int, CharT, bool>>();
  62 }
  63
  64 constexpr bool test() {
  65   test<char>();
  66 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  67   test<wchar_t>();
  68 #endif
  69
  70   return true;
  71 }
  72
  73 int main(int, char**) {
  74   test();
  75   static_assert(test());
  76
  77   return 0;
  78 }