text: // A fuzzer for floating-point formatter.
  // For the license information refer to format.h.
  
  #include <fmt/format.h>
  
  #include <cstdint>
  #include <cstdlib>
  #include <limits>
  #include <stdexcept>
  
  #include "fuzzer-common.h"
  
  void check_round_trip(fmt::string_view format_str, double value) {
    auto buffer = fmt::memory_buffer();
    fmt::format_to(std::back_inserter(buffer), format_str, value);
  
    if (std::isnan(value)) {
      auto nan = std::signbit(value) ? "-nan" : "nan";
      if (fmt::string_view(buffer.data(), buffer.size()) != nan)
        throw std::runtime_error("round trip failure");
      return;
    }
  
    buffer.push_back('\0');
    char* ptr = nullptr;
    if (std::strtod(buffer.data(), &ptr) != value)
      throw std::runtime_error("round trip failure");
    if (ptr + 1 != buffer.end()) throw std::runtime_error("unparsed output");
  }
  
  extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
    if (size <= sizeof(double) || !std::numeric_limits<double>::is_iec559)
      return 0;
    check_round_trip("{}", assign_from_buf<double>(data));
    // A larger than necessary precision is used to trigger the fallback
    // formatter.
    check_round_trip("{:.50g}", assign_from_buf<double>(data));
    return 0;
  }
  