On Thursday, 5 February 2015 at 01:33:54 UTC, Andrei Alexandrescu
wrote:
On 2/4/15 5:32 PM, deadalnix wrote:
On Thursday, 5 February 2015 at 01:07:56 UTC, Andrei
Alexandrescu wrote:
Yah, I agree "in" is useful for overridable functions. In
fact I'd say
it's useful _only_ for overridable functions.
Putting the contract in the caller is not only useful for
overridable
functions.
1/ If a lib is compiled in without contract, but your code is
compiled
with, you get the in contract to run when you call library
code, but not
the assert within the function.
2/ The optimizer see the properties of the argument when they
get to the
in contract. This information is lost in the callee, unless
inlining
goes on. that means the amount of contract the optimizer can
remove
statically is greater with in contract.
Yah, I understand the potential there. Consider me grudgingly
convinced :o). -- Andrei
I don't know about others (besides Beatophile, who religiously
adheres to writing contacts), but putting contracts on functions
is a hassle. I never do it unless I'm feeling particularly full
of divine fervor. It's a lot like making all variables that don't
need to be changed immutable (another thing which only Bearophile
seems to do) or properly documenting code. Strong optimization
guarantees from contracts would go a long way in convincing
people to actually write them (although I guess that's not what
you want; Perhaps you changed your mind). It's a chicken and egg
problem.
