Advanced const propagation for structs

[Timon Gehr via Digitalmars-d]

On 16.10.2016 14:18, Dicebot wrote:
> This issue has been discussed before in context of custom containers and
> AFAIK so far no one was able to come up with even theoretical concept of
> how it can be possibly addressed.

Actually, I did propose a solution before. Just allow annotations on 
template type parameters (to enable the new implicit upcasts) and check 
for binary compatibility of the respective template instances during 
implicit conversion.