🚀 go-pugleaf

Hello Peter

> It will not fail if the pB instance is implemented by a TInterfacedObject
> descendent.
>
> Type
>   TInterfacedObject = class(TObject, IInterface)
>

I changed the sample code and then with D7 as well with D5 I got an
assertion failure in the line marked with   *******

I can change
   TMyClass = class( TInterfacedObject, IDerived);
to
   TMyClass = class( TInterfacedObject, IDerived, IUnknown);
or to
   TMyClass = class( TInterfacedObject, IDerived, IInterface);
it doesn't matter - in all three cases the assertion comes up.

--- source ----

program Project1;
{$APPTYPE CONSOLE}
uses sysutils;

type
  IBase = interface( IUnknown)
    ['{D95F52B1-F337-4DE2-BF8D-1ACEF13F331A}']
  end;

  IDerived = interface( IBase)
    ['{47114A72-5557-4815-A734-76FE5745E2BA}']
  end;

  TMyClass = class( TInterfacedObject, IDerived);

  procedure TestIt( pB : IBase);
  var  pU : IUnknown;
  begin
     ASSERT( Supports( pB, IUnknown, pU));
     ASSERT( Supports( pU, IBase, pB));  // *******
  end;


var pD,pD2 : IDerived;
    pB,pB2 : IBase;
begin
  pD := TMyClass.Create;
  pB := pD;             // direct assignment works
  ASSERT( pB <> nil);
  ASSERT( Supports( pD, IDerived, pD2));
  TestIt( pD);
  ASSERT( Supports( pB, IBase, pB2));     // will fail
end.