Finding out ref-ness of the return of an auto ref function

[Stanislav Blinov]

On Friday, 12 June 2020 at 17:50:43 UTC, Arafel wrote:

> All in all, I still think something like 
> `__traits(isRef,return)` would still be worth adding! After all 
> the compiler already has all the information, so it's just 
> about exposing it. I'm trying to think of a library solution, 
> but I find it very hard to express "the hypothetical result of 
> calling the current function with the current parameters in the 
> current context".
>
> A.

If you're wrapping a function you can use a 
'getFunctionAttributes' trait [1], which would contain a "ref" if 
that function returns ref.

If, however, you're wrapping a function template, however, you 
won't know until you actually instantiate it, which is basically 
going back to Paul Backus' solution. So the compiler doesn't 
always have all the information :)

[1] https://dlang.org/spec/traits.html#getFunctionAttributes