Making preconditions better specified and faster

[Caspar Kielwein via Digitalmars-d]

On Sunday, 18 December 2016 at 10:47:42 UTC, Stefan Koch wrote:
> On Sunday, 18 December 2016 at 09:32:53 UTC, Caspar Kielwein 
> wrote:
>> On Thursday, 15 December 2016 at 18:48:22 UTC, Andrei 
>> Alexandrescu wrote:
>>> https://issues.dlang.org/show_bug.cgi?id=16975
>>
>> I'd love if preconditions where available at the caller. This 
>> would make it possible to use preconditions for input 
>> scrubbing, even in release builds with disabled asserts.
>
> That is exactly what they are not for.

I know that contracts are for specifying guarantees and 
conditions in regards to correctness of a program.

Still, at the first point where I call a function with user 
inputs, I often have to pretty much repeat the precondition of 
that function (but react different on violation) to scrub the 
inputs. I think it would be nice to be able to make the conscious 
choice of using the specified precondition for that.