Issue with implicit interface casting

[Etienne via digitalmars-d-ldc]

Hello,

I'm having this issue right now with LDC, it looks like interfaces are 
not cast properly in some cases to the original type when calling the 
methods.

I've elaborated it more here:

https://github.com/ldc-developers/ldc/issues/729

I'm hoping somebody can point me in a direction to resolve this. :)

Thanks !