Trying to use Mir ion, its a perfect example of the failure of D's attribute system

[Walter Bright]

On 1/20/2023 3:49 AM, Quirin Schroll wrote:
> 1. `process` cannot be virtual.

Virtual functions are meant to be overridden, meaning their attributes are 
inherited with covariant and contravariant rules. This is incompatible with 
attribute inference.

> 2. the argument bound to `callback` cannot have its parameter types inferred.

The version of this I posted can.