Merge pull request #659 from nikomatsakis/2020-07-29-lang-team-design-meetings

add two blog posts around recent lang team design meetings

Author: nikomatsakis

posts/inside-rust/2020-07-29-lang-team-design-meeting-min-const-generics.md

@@ -0,0 +1,32 @@
+---
+layout: post
+title: "Lang team design meeting: minimal const generics"
+author: Niko Matsakis
+description: "Minimal const generics meeting report"
+team: the lang team <https://www.rust-lang.org/governance/teams/lang>
+---
+
+Hello! Did you know that the [lang team] now has regular design
+meetings? We use these meetings to dig deeper into the output of
+active project groups. After the meeting, we typically post a
+recording to [YouTube] as well as some [minutes into the lang-team
+repository][min]. I wanted to write a quick update listing out some of
+the meetings we've had recently as well as some of our upcoming
+meetings.
+
+[YouTube]: https://www.youtube.com/playlist?list=PL85XCvVPmGQg-gYy7R6a_Y91oQLdsbSpa
+[lang team]: https://www.rust-lang.org/governance/teams/lang
+[min]: https://github.com/rust-lang/lang-team/tree/master/design-meeting-minutes
+
+This blog post is about the meeting we held on 2020-07-22. We
+discussed the idea of creating a "minimal const generics MVP", as
+proposed by boats in [a recent blog
+post](https://without.boats/blog/shipping-const-generics/).
+
+You can read the [minutes from the meeting] to learn more details or
+to find a link to the recording. In general, though, we were all
+pretty excited about the idea. I expect that we will be creating a
+project group soon around const generics and that its first goal will
+be working towards this MVP.
+
+[minutes from the meeting]: https://github.com/rust-lang/lang-team/blob/master/design-meeting-minutes/2020-07-22-Const-generics-MVP.md

posts/inside-rust/2020-07-29-lang-team-design-meeting-wf-types.md

@@ -0,0 +1,55 @@
+---
+layout: post
+title: "Lang team design meeting: well-formedness and type aliases"
+author: Niko Matsakis
+description: "Well-formedness and type aliases meeting report"
+team: the lang team <https://www.rust-lang.org/governance/teams/lang>
+---
+
+Hello! Did you know that the [lang team] now has regular design
+meetings? We use these meetings to dig deeper into the output of
+active project groups. After the meeting, we typically post a
+recording to [YouTube] as well as some [minutes into the lang-team
+repository][min]. I wanted to write a quick update listing out some of
+the meetings we've had recently as well as some of our upcoming
+meetings.
+
+[YouTube]: https://www.youtube.com/playlist?list=PL85XCvVPmGQg-gYy7R6a_Y91oQLdsbSpa
+[lang team]: https://www.rust-lang.org/governance/teams/lang
+[min]: https://github.com/rust-lang/lang-team/tree/master/design-meeting-minutes
+
+This blog post is about the meeting we held on 2020-07-29. We
+discussed the idea of trying to enforce the "well-formedness" rules
+for type aliases, as has been floated on and off over the years.
+
+The context is that the compiler's current rules expand type aliases
+as if they were a kind of macro, which means that we don't wind up
+enforcing many sorts of rules about them.
+
+For example, the following type alias definition is legal even though
+it would be an error to ever use it:
+
+```rust
+struct MyType<T: Display> { t: T }
+
+// This alias, perhaps, should err, as `Vec<u32>: Display`
+// does not hold:
+type MyAlias = MyType<Vec<u32>>;
+```
+
+For more information, check out the [minutes from the meeting] or
+[watch the recording]. We covered a number of examples of what goes
+wrong, as well as various possible "endstates" that we might want to
+reach (for example, there is an argument that the above example should
+be accepted after all, perhaps with a warning).
+
+The conclusion during the meeting was that we would not put a lot of
+energy into type aliases at this time, and in particular we wouldn't
+aim for any Edition-related migrations and hard-errors, but we would
+accept PRs that introduce warnings for type alias definitions that are
+always an error to use. (Like any conclusion that happens in a
+meeting, it may be revised if we encounter new evidence that changes
+our minds.)
+
+[minutes from the meeting]: https://github.com/rust-lang/lang-team/blob/master/design-meeting-minutes/2020-07-29-wf-checks-and-ty-aliases.md
+[watch the recording]: https://youtu.be/tIBZYQSA_eM