Hi Samuel,

> Bruno, it's a IMHO mandatory step in the direction of run-time specified
> geometries. But I intended to stick with the compile time checking with my
> current code (I'm working on runtime algo in an other branch whose state is
> far from becoming a PR !)
>
> I think that we could offer both options (and so two interfaces) and that
> without requiring a compile macro. But that means removing the MPL_ASSERT
> from not_implemented.
>
I agree it's important, and I agree the solution you're proposing sounds
promising. But there my be other approached, or not, I need to dig that.
This is why for now I prefer to have a consistent implementation and add
runtime support at a later point.

> I can postpone the integration of a 'global' is_implemented<> to a later
> stage (move it as an implementation detail of variant for distance). It
> sounds like it needs more thinking, no ?
>
Yep, I think so.

Regards
Bruno