> On Nov 28, 2018, at 11:25 PM, Sven Barth via fpc-pascal
> <fpc-pascal@lists.freepascal.org> wrote:
>
> You're not wrong, but a type alias is definitely the wrong way.
> But that is a completely different topic, one that I'm not willing to discuss
> right now, aside from "we don't support something like that”.
Ok, maybe something to think about later. Compile time performance could be a
reason to pursue down the road.
> If all that’s involved is comparing params types to generic types then that
> looks like a relatively simple solution. Const generic params may have
> complicated this some however.
>
> Yes, all generic parameters need to be part of the routine's parameters and
> constant parameters indeed won't work in that case.
What are the performance implications of specializing all these types across a
code base? I’ve heard c++ developers mention the terrible performance of
templates and I think that’s because of the inferred types and inability to
specialize once (like FPC does for all other generics except procs).
Looking at this now I think that each unit that uses an inferred specialization
will produce a unit procedure for just that unit. Is that right?
Here’s an example which specializes 3 generics (they’re shared right?) across 5
procedure calls.
generic procedure DoThis<T>(msg:T);
begin
end;
generic procedure DoThis<T>(msg:T;param1:T);
begin
end;
generic procedure DoThis<T>(msg:T;param1:integer);
begin
end;
begin
DoThis('hello'); // specialize DoThis<string>('hello');
DoThis(1); // specialize DoThis<integer>(1);
DoThis('a','b'); // specialize DoThis<string>('a','b’);
DoThis(1,1); // specialize DoThis<integer>(1,1);
DoThis('hello',1); // specialize DoThis<string>(‘hello',1);
Regards,
Ryan Joseph
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