C++ guys hate static_if?

[deadalnix]

On Thursday, 14 March 2013 at 17:53:42 UTC, Andrei Alexandrescu 
wrote:
> On 3/14/13 1:37 PM, deadalnix wrote:
>> On Thursday, 14 March 2013 at 17:07:16 UTC, Andrei 
>> Alexandrescu wrote:
>>> Very simple. Traditionally there's two crucial epochs known as
>>> compilation time and run time. (There's some minor 
>>> distinctions like
>>> link time etc.) The whole notion of concepts and other type 
>>> systems
>>> for templates is predicated on three crucial epochs: library
>>> compilation time, library user compilation time, and run 
>>> time. The
>>> logic goes, someone writes a generic library and wants to 
>>> distribute
>>> it to users. Users shouldn't ever see bugs caused by e.g. 
>>> typos in the
>>> library.
>>>
>>
>> I'm not sure if you are thinking I'm really stupid here.
>
> Being wrong doesn't make one stupid.
>

I may be wrong, but certainly not because I don't make the 
difference between compile time and run time.

> Template constraints are D's solution to that issue. I agree 
> it's not perfect, but I think dollar for dollar it's better 
> than concepts.
>

No they aren't, because it would only skip the top most lines and 
replace the error by something like impossible to find method 
blah.

With something like concept, I'd have something like in case of 
eroneous template :
file:line: Error: concept Blah don't have member blah.

Or in the case of unmatched constraint :
file:line: Error: template Blah except a concept argument of 
meta-type Foo, Bar given.

And in both cases you can avoid the dreaded wall of error.