[fpc-devel] generics defy scoping rules -- Intended?

[Hairy Pixels]

 On Nov 25, 2025 at 9:55:46 PM, Martin Frb via fpc-devel <
fpc-devel at lists.freepascal.org> wrote:

> Thanks, which just for confirmation brings up a follow up question. (I
> haven't used generic function much yet, so maybe I miss something)
>
>           function  Foo   (aParam: Integer): integer;
>   generic function  Foo<T>(aParam: t)      : integer;
>
>
> Those are 2 different function too? (not an overload? because "T" could be
> integer in same cases)
>
> Do you then always have to call the generic using
>   specialize Foo<integer>(1)
> ?
>
> I seem to remember a discussion about adding automatic specialization?
> But then
>   foo('abc') // would be clear, to specialize with string
> but
>   foo(1)  // could be either
> _______________________________________________
>


yes those are two different functions. The generic function is just a
template which includes the parsed tokens and is named with $X where X is
the number of generic parameters. Only at the time of specialization is the
code generated, until the it's just an array of tokens.

there is a {$modeswitch implicitfunctionspecialization} mode switch ( my
work so I apologize for the bugs 😂) which infers the parameter type so
that foo('abc') becomes foo<String>('String').
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