David Abrahams wrote: > "Edward Diener" <[EMAIL PROTECTED]> writes: > >>> I browsed the article (I confess to not having read everything, so >>> please correct any misapprehensions). My sense is that the >>> technique >>> is oriented towards detecting programmer errors and responding via >>> an exception. >> >> I don't think ENFORCE is oriented toward that at all. There's no >> orientation involved other than to throw an exception based on a >> condition. I agree with you that direct programming errors should >> generally not throw exceptions but should ASSERT so that the >> programmer can fix the error. However I don't think ENFORCE has >> anything to do with this debate about when to ASSERT and when to >> throw exceptions. Perhaps the examples give the impression which you >> have > > I think so. > >> but I think the problem is just choosing better examples in which >> one would want to throw an exception and not a technical issue as to >> the benefits of using ENFORCE in order to simplify exception >> throwing. > > Can you show me a better example? This is not a challenge. Really, > if this ENFORCE idea is a useful one I want to understand it.
A typical example might be a 3rd party library in which an end-user passes a std::string, call it "s", which must contain some valid data and not be empty. In this case I would throw an exception since it is not my error but my end-user's error. Say my exception, derived from std::runtime_error is eSomeEmptyString. I could then write: Enforce<eSomeEmptyString>(!s.empty(),"My Message"); To me this is a nice shorthand notation for throwing an exception when the "s" string is empty, ie. contains no data. I believe Mr. Alexandrescu developed Enforce as a nice way of regularizing the code when an exception must be thrown based on a condition. The code becomes more readable and easier to understand. For me such constructs, although not revolutionary in and of themselves, are important in making cleaner and more understandable coding and I appreciate Mr. Alexandrescu's efforts in such an area. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
