[fpc-pascal] Check In Interface Type Helpers

[Marcos Douglas B. Santos]

On Wed, Aug 23, 2017 at 3:25 PM, Sven Barth via fpc-pascal
<fpc-pascal at lists.freepascal.org> wrote:
> On 23.08.2017 19:57, Marcos Douglas B. Santos wrote:
>> Would we have any problem of memory leaks using Interface helper with
>> COM interfaces (refcount)?
>> I mean, the "type helper" has constructor/destructor to create/release
>> something?
>
> It doesn't need to. A type helper is essentially syntactic sugar for a
> class method with the extended parameter as first type.

So, is this work?

=== code begin ===

type
  IFoo = interface
    function Execute: IFoo;
  end;

  TFooHelper = type helper for IFoo
    procedure Something;
  end;

  TFoo = class(TInterfacedObject, IFoo)
  public
    function Execute: IFoo;
  end;

var
  F: IFoo;
begin
  F := TFoo.Create;
  F.Execute.Something;
end;

=== code end ===