[fpc-pascal] Feature announcement: implicit generic function specializations

[Mattias Gaertner]

On Wed, 20 Apr 2022 19:15:15 +0200
Sven Barth via fpc-pascal <fpc-pascal at lists.freepascal.org> wrote:

>[...]
> This feature is enabled with the modeswitch 
> ImplicitFunctionSpecialization and is for now not enabled by default
> as this has the potential to break existing code.

Sad. This feature really makes generic functions shine.

 
>[...]
> generic function ArrayFunc<T>(aArg: specialize TArray<T>): T;
>[...]
> type
>    generic TTest<T> = function(aArg: T): T;
> 
> generic function Apply<T>(aFunc: specialize TTest<T>; aArg: T): T;
>[...]
> begin
>    Writeln(ArrayFunc([1, 2, 3])); // will write 6
>    Writeln(ArrayFunc(['Hello', 'FPC', 'World'])); // will write 
> HelloFPCWorld
> 
>    Writeln(Apply(@StrFunc, 'Foobar')); // will write FOOBAR
>    Writeln(Apply(@NegFunc, 42)); // will write -42
> end.

Mind boggling. :)

Mattias