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Explain error with &mut self for unsized trait impls

This commit is contained in:
clubby789 2023-01-03 17:02:25 +00:00
parent b435960c4c
commit 23c3a30730
3 changed files with 43 additions and 11 deletions

View file

@ -344,20 +344,25 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
} else {
err.span_help(source_info.span, "try removing `&mut` here");
}
} else if decl.mutability == Mutability::Not
&& !matches!(
} else if decl.mutability == Mutability::Not {
if matches!(
decl.local_info,
Some(box LocalInfo::User(ClearCrossCrate::Set(BindingForm::ImplicitSelf(
hir::ImplicitSelfKind::MutRef
))))
)
{
err.span_suggestion_verbose(
decl.source_info.span.shrink_to_lo(),
"consider making the binding mutable",
"mut ",
Applicability::MachineApplicable,
);
),)))
) {
err.note(
"as `Self` may be unsized, this call attempts to take `&mut &mut self`",
);
err.note("however, `&mut self` expands to `self: &mut Self`, therefore `self` cannot be borrowed mutably");
} else {
err.span_suggestion_verbose(
decl.source_info.span.shrink_to_lo(),
"consider making the binding mutable",
"mut ",
Applicability::MachineApplicable,
);
};
}
}