libcxx/test/std/utilities/format/format.range/format.range.fmtdef/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<ranges::input_range R, class charT>
  16 //   struct range-default-formatter<range_format::sequence, R, charT>
  17
  18 // template<class ParseContext>
  19 //   constexpr typename ParseContext::iterator
  20 //     parse(ParseContext& ctx);
  21
  22 #include <array>
  23 #include <cassert>
  24 #include <concepts>
  25 #include <format>
  26 #include <memory>
  27
  28 #include "test_macros.h"
  29 #include "make_string.h"
  30
  31 #define SV(S) MAKE_STRING_VIEW(CharT, S)
  32
  33 template <class StringViewT>
  34 constexpr void test_parse(StringViewT fmt, std::size_t offset) {
  35   using CharT    = typename StringViewT::value_type;
  36   auto parse_ctx = std::basic_format_parse_context<CharT>(fmt);
  37   std::formatter<std::array<int, 2>, CharT> formatter;
  38   static_assert(std::semiregular<decltype(formatter)>);
  39
  40   std::same_as<typename StringViewT::iterator> auto it = formatter.parse(parse_ctx);
  41   // std::to_address works around LWG3989 and MSVC STL's iterator debugging mechanism.
  42   assert(std::to_address(it) == std::to_address(fmt.end()) - offset);
  43 }
  44
  45 template <class CharT>
  46 constexpr void test_fmt() {
  47   test_parse(SV(""), 0);
  48   test_parse(SV(":5"), 0);
  49
  50   test_parse(SV("}"), 1);
  51   test_parse(SV(":5}"), 1);
  52 }
  53
  54 constexpr bool test() {
  55   test_fmt<char>();
  56 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  57   test_fmt<wchar_t>();
  58 #endif
  59
  60   return true;
  61 }
  62
  63 int main(int, char**) {
  64   test();
  65   static_assert(test());
  66
  67   return 0;
  68 }