Eliminate assert and lazy from D?

[Andrei Alexandrescu]

Frank Benoit wrote:
> Andrei Alexandrescu schrieb:
>> Right now, the language has enough power to express assert as a library
>> function, as opposed to a primitive construct. (See e.g. enforce.) I
>> think it would be good to relegate assert to object.d.
>>
>> This also brings up "lazy", which seems to be quite botched. Are there
>> suggestions on how to replicate its functionality in a different way? I
>> even seem to recall lazy was discussed as a disadvantage in the recent
>> dialog on reddit, see
>>
>> http://www.reddit.com/r/programming/comments/9qf8i/i_wrote_some_d_today_and_its_completely_blowing/
>>
>>
>> I personally believe it's useful to be able to pass an unevaluated
>> expression into a function, for example assert and enforce themselves
>> use that.
>>
>> But let's open this for discussion: should assert and/or lazy be
>> removed? If not, why not? It yes, why? How can we replicate their
>> functionality?
>>
>>
>> Andrei
> 
> I have seen lazy only used in its own show case. In log functions. In
> Tango too it is used in log functions. I use delegates as function
> parameters often, but not lazy. This is because I may add parameters and
>  on the caller site, IMO it must be obvious, this expression is not
> evaluated as others. Maybe it is acceptable to remove lazy and write
> logging statements with delegate and the curly braces.
> log({ "bla bla "~info });

std.contracts.enforce also uses it.

> A related issue with passing arguments, that i think needs a better
> solution in D are the variadic arg list. No magic param names and the
> possibility to pass this list - or a slice of it - to another function.

I'm hoping that template variadics + arrays of Variant cover all needs.


Andrei