On Sun, 17 Sep 2017 08:44:47 -0700, c...@zoffix.com wrote: > More comments on similar issue: https://irclog.perlgeek.de/perl6/2017- > 09-17#i_15176823 > > Basically, a lot of core constructs aren't workable with user-land > subclasses.
Note on the performance concerns... if we had a faster-than-a-where-clause type smiley (or other mechanism) that only accepted the exact type, not subclasses, then the core could provide very optimized implementations for core types as separate candidates, and a more generic implementation for subclasses, which would be slower but less likely to be affected by internals churn.
