On Fri Jun 19, 2026 at 8:08 AM JST, Danilo Krummrich wrote: > Devres<T> stores resources as T and returns &'a T from access(). For > lifetime-parameterized types like Bar<'a, SIZE> that are transmuted to > 'static for storage, this exposes the synthetic 'static lifetime to > callers -- any method on the stored type that returns a reference with > its lifetime parameter would yield a &'static reference, which is > unsound. > > Add DevresLt<F: ForLt>, a thin wrapper around Devres<F::Of<'static>> > that shortens the stored 'static lifetime to the caller's borrow > lifetime in all access methods. > > DevresLt::new() is unsafe because the caller must guarantee that the > data remains valid for the device's full bound scope; the internal > transmute from F::Of<'a> to F::Of<'static> would otherwise allow > use-after-free. > > Two access patterns are provided: > > - CovariantForLt types get direct-reference accessors (access, > try_access) that return shortened references via > CovariantForLt::cast_ref. > > - Plain ForLt types use closure-based accessors (access_with, > try_access_with) whose universally quantified lifetime prevents > callers from smuggling in concrete short-lived references. > > Signed-off-by: Danilo Krummrich <[email protected]>
Reviewed-by: Alexandre Courbot <[email protected]>
