void basic_writer::write_double()

in src/main/cpp/sdk/common/spdlog/fmt/bundled/format.h [2698:2756]

• 50 lines of code
• 19 McCabe index (conditional complexity)

void basic_writer<Range>::write_double(T value, const format_specs &spec) {
  // Check type.
  float_spec_handler handler(static_cast<char>(spec.type));
  internal::handle_float_type_spec(handler.type, handler);

  char sign = 0;
  // Use signbit instead of value < 0 because the latter is always
  // false for NaN.
  if (std::signbit(value)) {
    sign = '-';
    value = -value;
  } else if (spec.has(SIGN_FLAG)) {
    sign = spec.has(PLUS_FLAG) ? '+' : ' ';
  }

  struct write_inf_or_nan_t {
    basic_writer &writer;
    format_specs spec;
    char sign;
    void operator()(const char *str) const {
      writer.write_padded(spec, inf_or_nan_writer{sign, str});
    }
  } write_inf_or_nan = {*this, spec, sign};

  // Format NaN and ininity ourselves because sprintf's output is not consistent
  // across platforms.
  if (internal::fputil::isnotanumber(value))
    return write_inf_or_nan(handler.upper ? "NAN" : "nan");
  if (internal::fputil::isinfinity(value))
    return write_inf_or_nan(handler.upper ? "INF" : "inf");

  memory_buffer buffer;
  bool use_grisu = FMT_USE_GRISU && sizeof(T) <= sizeof(double) &&
      spec.type != 'a' && spec.type != 'A' &&
      internal::grisu2_format(static_cast<double>(value), buffer, spec);
  if (!use_grisu) {
    format_specs normalized_spec(spec);
    normalized_spec.type = handler.type;
    internal::sprintf_format(value, buffer, normalized_spec);
  }
  size_t n = buffer.size();
  align_spec as = spec;
  if (spec.align() == ALIGN_NUMERIC) {
    if (sign) {
      auto &&it = reserve(1);
      *it++ = static_cast<char_type>(sign);
      sign = 0;
      if (as.width_)
        --as.width_;
    }
    as.align_ = ALIGN_RIGHT;
  } else {
    if (spec.align() == ALIGN_DEFAULT)
      as.align_ = ALIGN_RIGHT;
    if (sign)
      ++n;
  }
  write_padded(as, double_writer{n, sign, buffer});
}