Error: need this for method of type

[Dennis]

On Wednesday, 23 October 2019 at 11:40:09 UTC, Márcio Martins 
wrote:
> This is a bug, right? If not, why, and how can I get around it 
> and call `method`?

An alias refers just to a symbol, in this case a member function 
of struct X.
The fact that you polled it on instance 'x' is not something an 
alias keeps track of.
You can change `method(1)` into `x.method(1)` and it should work.