Question

I am writing some library functions that needs to do some error reporting. I want to use exceptions rather than return values.

I wrote my functions that throws int exceptions.

Eg:

if(strm->atEnd()){
    // unexpected end of stream
    throw -2;
}

My question is, is this method OK? Or should I throw a exception derived from std::exception?

In what way is throwing a std::exception better? (Other than being able to use catch(std::exception &e))

Is throwing int exceptions bad practice? (all throw int values are documented in doxygen comments)

I can’t find any reason as to why (in this case) should I throw an object.

Answer 1

I would throw an exception based on std::exception.

throw std::runtime_error("unexpected end of stream")

I find this easier to catch, log, et cetera. It also allows the removal of a comment and a magic number from the code.

This message can then be sent to the end-user to give them a hope of fixing the problem.

Users and library consumers can’t read the comments in code, and they are unlikely to know what ‘-2’ means.