Optional tags and attributes

[Steven Schveighoffer]

On Fri, 17 Jan 2014 21:50:07 -0500, Stanislav Blinov  
<stanislav.blinov at gmail.com> wrote:

> On Saturday, 18 January 2014 at 02:38:28 UTC, H. S. Teoh wrote:
>
>> What's wrong with just letting the compiler infer the maximal function
>> attributes?
>
> ...
>
>> Sadly, this only works for template functions currently -- so I still
>> had to annotate the various method()'s by hand, but if you were to turn
>> them into template functions too, their attributes will also be inferred
>> automatically.
>
> Oh, I see now where it went the wrong way. From my own example, of  
> course :)
>
> Surely I was meaning:
>
> class Careful(T) {
> //...
>    void thisIsSoPolymorphic() nothrow(isNoThrow!(T.foo)) { ... }
> //...
> }
>
> Something to that extent. So that yes, the function itself is not a  
> template.

I was about to respond with a similar point, but it seems you are  
understanding now how the nothrow inference works :)

I can't think of a correct way to do this without repeating code, since it  
has to be polymorphic (and therefore not a template), nothrow inference  
only works on templates.

The idea to be able to attach attributes/annotations based on compile-time  
introspection would be a worthy addition to the language IMO, but I really  
don't like the syntax you have outlined (I see you don't like it either).  
Especially if you have to do all the attributes this way.

I think a "use the attributes of X" would be a general enough tool.

Something like:

  void thisIsSoPolymorphic() attrOf(T.foo)

-Steve