Good Contract programming idiom?

[Lars T. Kyllingstad]

dsimcha wrote:
> == Quote from Fawzi Mohamed (fawzi at gmx.ch)'s article
>> I already thought that having a aassert (always assert) would
>> be nice...
> 
> In D2, isn't that what enforce() is for?

It is indeed.

I've found enforce() to be extremely practical.  I use it every time I 
would otherwise write

   if (some test fails) throw new Exception("Some test failed");

Besides being slightly shorter than the above, it saves me the trouble 
of providing the file and line number where the error occurred.  Also, 
its sibling errnoEnforce() is invaluable when working directly with C 
functions, where the alternative is

   if (some test fails) throw new Exception(to!string(strerror(errno)));

In fact, there are a lot of goodies in std.contracts that I suspect most 
people aren't aware of.

-Lars