fix: Catch #[rustc_reservation_impl = "reason"]#22282
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ChayimFriedman2 merged 1 commit intorust-lang:masterfrom May 4, 2026
Merged
fix: Catch #[rustc_reservation_impl = "reason"]#22282ChayimFriedman2 merged 1 commit intorust-lang:masterfrom
#[rustc_reservation_impl = "reason"]#22282ChayimFriedman2 merged 1 commit intorust-lang:masterfrom
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And not just `#[rustc_reservation_impl]`. This has caused a bug that took me way too long to debug. Basically, with the reservation impl `From<!> for T` overlapping with `From<T> for T`, the solver couldn't deduce from the bound `Ty: From<?var>` that `var = Ty`. Up until now this only caused some unknown types, but with the "type annotations needed" it started becoming visible, and annoying. This is not the first time that we forget some attribute can be applied in more than one reason; perhaps we should unify handling for all `ast::Meta` kinds that have a path.
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And not just
#[rustc_reservation_impl].This has caused a bug that took me way too long to debug. Basically, with the reservation impl
From<!> for Toverlapping withFrom<T> for T, the solver couldn't deduce from the boundTy: From<?var>thatvar = Ty. Up until now this only caused some unknown types, but with the "type annotations needed" it started becoming visible, and annoying.This is not the first time that we forget some attribute can be applied in more than one reason; perhaps we should unify handling for all
ast::Metakinds that have a path.Fixes #22263.