On Wednesday 14 March 2007 15:05 pm, Hartmut Kaiser wrote:
Frank Mori Hess wrote:
I have to say I really am not a big fan of needless overloading of the languages operators like logical || and &&. Especially when you are overloading them with functions that really don't correspond to the original operators. What if I want to overload || with a function that actually does correspond to logical or, like
Future<bool> operator||(const Future<T> &a, const Future<U> &b);
1. Why do you would do that? Do you have a use case?
Making active functions that take futures as arguments and return futures as return values is the primary feature of libpoet. See http://www.comedi.org/projects/libpoet/ So the operator|| above would be used if you wanted to || two results and pass the result of the || to another active function without blocking waiting for the futures to become ready. Really it was just an example though, I'm not currently planning to implement this (although maybe I will someday if I discover it to be useful).
2. If you really have to do that, simply do not include the header(s) defining the operators.
I don't really have to define an operator||, I could just give the function an ordinary name. My point is, composing futures like in Thorsten Schütt's implementation doesn't really have to define an operator|| either. And, if I had to choose which function had a more legitimate claim to use operator||, I'd choose my example. Not including the headers isn't really a solution, since it precludes the use of the conflicting functions in the same code. Pointless overloading isn't a good thing. What does it buy you here? A pair of parenthesis. -- Frank