assert(condition[, message]) patch

[Sean Kelly]

Walter Bright wrote:
> braddr at puremagic.com wrote:
>> I have been toying with D to bring myself up to speed and I found 
>> myself writing
>> a lot of unit tests, always a good thing.  In those unit tests I found 
>> myself
>> writing a lot of blocks like:
>>
>> if (cond)
>> {
>> writefln("some debugging output to make my life easier");
>> assert(false);
>> }
>>
>> I know many don't like unit tests to have output, but I do.
> 
> Why not:
> 
>     assert(!cond); // some debugging output to make my life easier
> 
> ? You'll need to go look at the source anyway when the assert trips, so 
> what advantage is there to print the comment?

Some applications ship with asserts left on, and the more information 
the user has about why the application just halted the better.  As 
others have noted, an optional message also allows state information to 
be conveyed, which can be useful in the absence of a core dump.


Sean