Am 17.03.2011 02:55, schrieb Andrei Alexandrescu:
On 03/16/2011 08:50 PM, Daniel Gibson wrote:
Am 17.03.2011 02:07, schrieb Andrei Alexandrescu:
On 03/16/2011 06:45 PM, bearophile wrote:
- Where it is used it usually doesn't give a more meaningful exception
like WrongArgumentException, etc. I don't want a deep hierarchy of one
hundred standard exceptions, but I think some standard exceptions for
the most common mistakes, like wrong arguments, etc, are better than a
generic enforce(), especially for a standard library code that is
meant to be written with care and to give better error
messages/exceptions.
enforce helps such idioms, does not prevent them. From the docs:
===============
T enforce(T)(T value, lazy Throwable ex);
If value is nonzero, returns it. Otherwise, throws ex.
===============
Really?
using enforce with a custom throwable saves *one* char:
enforce(foo, new BlaException("bad!"));
if(!foo) throw new BlaException("bad!");
or are there other merits?
enforce is an expression that returns its argument so it's composable.
Andrei
You're right. I just realized it and wanted to reply that correction to
myself but you were faster :)
I agree, that *is* helpful.
A side note: The documentation says the value is returned if it's
"non-zero".
enforce() also throws on null (for classes, probably also for pointers)
and false (for bool..) - this should probably be mentioned in the docs ;-)
Cheers,
- Daniel
