operator>> writes to stderr

[wolframroesler]

Hi,

is it intentional that operator>> writes to stderr before throwing an exception in 1.8.3? IMHO it shouldn't do that - it's an unexpected side effect, and it messes up the application's error output. Not every bad input to the JSON parser is an error I want logged on stderr. No other JsonCpp function writes anything to stderr before throwing. Also, it didn't do that in 1.8.0. Also, it uses fprintf which it not really C++-like (which makes me hope it's just some forgotten debug output).

I suggest removing the fprintf(stderrr,...), or #ifdefing it out if you really need it.

Thanks

Wolfram

JSONCPP_ISTREAM& operator>>(JSONCPP_ISTREAM& sin, Value& root) {
  CharReaderBuilder b;
  JSONCPP_STRING errs;
  bool ok = parseFromStream(b, sin, &root, &errs);
  if (!ok) {
    fprintf(stderr,
            "Error from reader: %s",
            errs.c_str());

    throwRuntimeError(errs);
  }
  return sin;
}

[wolframroesler]

Submitted it as a pull request: #666

[cdunn2001]

It's been there since 2011: 2b853c4

But I think it was an accident. The idea was, back then, exceptions could be turned off/on with a macro. A stream operator has no way to indicate failure, so we wrote to stderr in case. But I don't think that has been needed or helpful in many years.

Thanks for noticing.