rust-lang / rust-lang/rust

`InferCtxt::region_constraints_added_in_snapshot` ignores type outlives obligations

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A-inference T-compiler T-types
Dominant language
Rust
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Description

This function should also consider region obligations added in InferCtxtInner::region_obligations

https://github.com/rust-lang/rust/blob/3340d49d22b1aba425779767278c40781826c2f5/compiler/rustc_infer/src/infer/mod.rs#L920-L927

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Research direction

Start with InferCtxt::region_constraints_added_in_snapshot in compiler/rustc_infer/src/infer/mod.rs at the linked lines, then inspect InferCtxtInner::region_obligations. Confirm how the snapshot currently tracks region constraints and update the behavior so type outlives obligations added there are considered; done means those obligations are included in the function's result.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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