forked off of T-compiler discussion
cc @nikomatsakis @Matthew Jasper
What did you mean, @Matthew Jasper, by auto traits being perma-unstable? I guess you mean that we're kind of tinkering with what types you see when you use a
static mut, and the main way we justify that is by knowing what send/sync care about? (maybe)
Yes, if we know all of the auto traits that exist then we can make arguments based on what specifically they care about.