New concepts are undocumented

[metagn]

New concepts as described in nim-lang/RFCs#168 are in the language (#15251) but undocumented, the experimental manual only describes old concepts.

[foxoman]

Any update on this ? or has it been done ?

[ringabout]

Nope

[evelant]

As a newcomer to nim if I hadn't been browsing the RFCs out of curiosity I never would have known! Concepts seemed like a really powerful feature and it turns out they're even more powerful than I thought due to the missing docs.