On Tue, Jul 23, 2024 at 09:36:21AM +0000, Quirin Schroll via Digitalmars-d wrote:
> From [D Language Foundation March 2024 Monthly Meeting Summary](https://forum.dlang.org/post/qwyhlvqintqsnzwnzuwv@forum.dlang.org)
> > Walter said the way to do that was to have the compiler recognize the template and not instantiate it, but just return the result. He'd done that for a couple of the templates. `Unqual` sounded like a good candidate for that. Then it would still look like a template, but it wouldn't have the cost of a template anymore.
> 
> That’s not a good solution, it’s just whack-a-mole. Why not add a pragma so that any template can be like that at the programmer’s discretion?  `pragma(nocache)` or something like that. We can add it to any Phobos template and D programmers can add it in their code bases where they see fit.

Doubt that would make much of a difference.  DMD uses the "allocate and forget" strategy of memory allocation; it doesn't even matter if something is not cached, if memory was allocated while computing it, that memory will stick around.  Might as well cache it so that you don't spend even more memory afterwards to recompute it.


T

-- 
Once bitten, twice cry...

On 23/07/2024 9:36 PM, Quirin Schroll wrote:
>  From [D Language Foundation March 2024 Monthly Meeting Summary](https://forum.dlang.org/post/qwyhlvqintqsnzwnzuwv@forum.dlang.org)
>> Walter said the way to do that was to have the compiler recognize the template and not instantiate it, but just return the result. He'd done that for a couple of the templates. `Unqual` sounded like a good candidate for that. Then it would still look like a template, but it wouldn't have the cost of a template anymore.
> 
> That’s not a good solution, it’s just whack-a-mole. Why not add a pragma so that any template can be like that at the programmer’s discretion? `pragma(nocache)` or something like that. We can add it to any Phobos template and D programmers can add it in their code bases where they see fit.

Turning off caching requires template instantiation to occur. It does not change that.

The point is to recognize a template instantiation request as a ``__trait`` which is very cheap to do on the compiler side.

So no, turning off caching wouldn't be beneficial.

On Tuesday, 23 July 2024 at 16:00:39 UTC, Richard (Rikki) Andrew Cattermole wrote:
>
> Turning off caching requires template instantiation to occur. It does not change that.
>
> The point is to recognize a template instantiation request as a ``__trait`` which is very cheap to do on the compiler side.
>
> So no, turning off caching wouldn't be beneficial.

+1

In general turning off template caching is never beneficial. I have experimented with that in my time.