April 7: Design meeting for Chalk const support

[jackh726]

This is a meta-issue to basically keep track of when we should have this meeting and that is has/hasn't happened.

[detrumi]

the const generics RFC

[jackh726]

Conversation link: https://rust-lang.zulipchat.com/#narrow/stream/144729-wg-traits/topic/design.20meeting.202020.2E04.2E07/near/193239347

This issue can be closed when the meeting notes get added.

[nikomatsakis]

Update:

• had meeting (zulip logs) and designed a minimal subset
• have a pending PR, #393

[nikomatsakis]

Update:

• prereq for landing the PR refactor ParameterKind to match rustc, accomodate constants chalk#452