Function WriteFloatToBuffer

src/common/base/string_number.cc:254–270

------------------------------------------------------------- Float to string or buffer. Makesure buffer size >= kMaxFloatStringSize -------------------------------------------------------------

// Makesure buffer size >= kMaxFloatStringSize
// -------------------------------------------------------------
char* WriteFloatToBuffer(float value, char* buffer) {
  // FLT_DIG is 6 on almost all platforms.
  // If it's too big, the buffer will overflow
  //     STATIC_ASSERT(FLT_DIG < 10, "FLT_DIG is too big");
  if (value >= numeric_limits<double>::infinity()) {
    strcpy(buffer, "inf");  // NOLINT
    return buffer + 3;
  } else if (value <= -numeric_limits<double>::infinity()) {
    strcpy(buffer, "-inf");  // NOLINT
    return buffer + 4;
  } else if (IsNaN(value)) {
    strcpy(buffer, "nan");  // NOLINT
    return buffer + 3;
  }

  return buffer + snprintf(buffer, kMaxFloatStringSize, "%.*g", FLT_DIG, value);
}

char* DoubleToString(double n, char* buffer) {
  WriteDoubleToBuffer(n, buffer);