Reimplementing the bulk of std.meta iteratively

[Andrei Alexandrescu]

On 9/26/20 6:00 PM, Steven Schveighoffer wrote:
> On 9/26/20 5:42 PM, Andrei Alexandrescu wrote:
>> On 9/26/20 5:16 PM, Timon Gehr wrote:
>>> On 26.09.20 18:18, Andrei Alexandrescu wrote:
> Such things are not *impossible*, but something like derivative is a 
> great example that is really difficult to generate a runtime function 
> that can do it.

Yah, you'd need i.e. a member function in Id called bool 
implicitlyConvertible(Id another). The functionality needed is similar 
to that in Variant, which created the need for implicitConversionTargets 
(https://dlang.org/library/std/traits/implicit_conversion_targets.html). 
You'd need to have access to those in the Id space.