Impl Trait aka Look ma’, no generics! by Jon Gjengset

#rust #rustlang #programming
Slides: https://jon.thesquareplanet.com/slide...
Hosted at DIKU (University of Copenhagen) on the 28th of September 2023

0:00:00 Introduction
0:01:02 Return position impl Trait
0:14:41 Argument position impl Trait
0:17:04 Associated type impl Trait
0:23:05 Type alias impl Trait
0:28:50 Return position impl Trait in traits
0:33:41 Asynchronous functions in traits
0:37:09 Q&A
0:37:41 Q: Should I push back on adopting impl Trait?
0:40:15 Q: Existentials in argument position
0:41:40 Q: Will +'a in return position become an error?
0:43:14 Q: Can the hidden type vary by generic params?
0:44:24 Q: What does +'a actually mean?
0:45:11 Q: Why does +'a mostly work?
0:45:57 Q: Can I just put +'static?
0:47:16 Q: Do we need inverse syntax for +'a?
0:48:02 Q: Will the edition upgrade require code change?
0:49:03 Q: Can two async blocks map to one hidden type?
0:51:49 Q: What happens if there is no defining use?
0:52:29 Q: Will ambiguous defining uses "just work"?
0:54:15 Q: How can fn eat take an existential type?
0:57:04 Q: Can I use existential types in let?
0:58:22 Q: Auto-traits and backwards compatibility
0:59:16 Q: What if we replace Self::IntoIter with impl?
1:00:30 Q: Is taking an existential as an argument bad?
1:01:21 Q: Why is this hard for IDEs?
1:02:32 Q: Interaction with self-defined auto traits
1:05:50 Q: Will you be signing books for beers?
1:06:12 Q: Is the counter you keep for signed or sold books?
1:06:47 Q: I currently write return position impl trait and I often have to write +'a, is that wrong?