rust/compiler/rustc_hir_analysis
Matthias Krüger ca7e27a71c
Rollup merge of #113182 - compiler-errors:rpit-stricter-captures, r=oli-obk
Error when RPITITs' hidden types capture more lifetimes than their trait definitions

This implements a stricter set of captures rules for RPITITs. They now may only capture:
1. Lifetimes from the impl header (both the self type and any trait substs -- we may want to restrict just to the self type's lifetimes, but the PR makes that easy to do, too)
2. Lifetimes mentioned by the `impl Trait` in the trait method's definition.

Namely, they may not mention lifetimes from the method (early or late) that are not mentioned in the `impl Trait`.

cc #105258 which I think was trying to do this too, though I'm not super familiar with what exactly differs from that or why that one was broken.
cc #112194 (doesn't fix this issue per se, because it's still an open question, but I think this is objectively better than the status quo, and gets us closer to resolving that issue.)

Technically is a fix for the ICE in #108580, but it turns that issue into an error now. We can decide separately whether or not nested RPITITs should capture lifetimes from their parents.

r? ``@oli-obk``
2023-07-01 13:46:01 +02:00
..
src Rollup merge of #113182 - compiler-errors:rpit-stricter-captures, r=oli-obk 2023-07-01 13:46:01 +02:00
Cargo.toml drop unused deps, gate libc under unix for one crate 2023-04-22 15:22:21 +03:00
messages.ftl Rollup merge of #113071 - compiler-errors:no-parent-non-lifetime-args-in-apit, r=eholk 2023-06-30 08:01:13 +02:00
README.md rustc_typeck to rustc_hir_analysis 2022-09-27 10:37:23 +02:00

For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.