on Mon Jul 28 2008, "Emil Dotchevski" <emil-AT-revergestudios.com> wrote:
Assertions are for precondition violations -- they detect programming errors. Exceptions are for failure to satisfy postconditions. They're really very different.
Since we don't have a category for detecting and reporting failures, it seems a good idea to create one. I'm all for a better name for it, of course.
The problem is that the exception lib doesn't belong in any of the existing categories, except maybe the Miscellaneous category. :)
Well, maybe that's where it belongs. static assert and Boost.Test are in the category of something like "program validation and testing" and don't belong in the same category as something designed for dealing with resource exhaustion and other essentially non-preventable and (hopefully) recoverable conditions.
Yes, exceptions are used to enforce postconditions,
"Enforce" isn't the best word; they bail you out when you're not going to meet postconditions, so you can avoid failure.
but this doesn't contradict the view that exceptions are used to report failures (to meet postconditions).
You might notice that I said "exceptions are for failure to satisfy postconditions" above :-) That said, they're really for avoiding failure, as noted in this message.
There are different kinds of failures,
Radically. And people tend to collapse them in their minds.
but despite the differences there is some commonality between asserts, static asserts, exceptions, signals, std::cerr, logging, abort(), exit(), etc. Naming a category "error reporting" seems to capture that, and it seems more descriptive than "miscellaneous" (and from that point of view static assert would belong to both "error reporting" and "program validation and testing".)
How about "diagnostics?" -- Dave Abrahams BoostPro Computing http://www.boostpro.com