The `TyCtxt::hir_get_fn_id_for_return_block()` function was too broad,
as it will return positively even when given part of an expression that
can be used as a return value. A new
`potential_return_of_enclosing_body()` utility function has been made to
represent the fact that an expression might be directly returned from
its enclosing body.
changelog: [`return_and_then`]: prevent false positives in case of a
partially used expression
Fixesrust-lang/rust-clippy#15111Fixesrust-lang/rust-clippy#14927
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### Summary Notes
-
[Beta-nomination](https://github.com/rust-lang/rust-clippy/pull/15115#issuecomment-2996222332)
by [samueltardieu](https://github.com/samueltardieu)
*Managed by `@rustbot`—see
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