diff options
| -rw-r--r-- | src/librustc_typeck/check/method/mod.rs | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs index 434ead50e04..e57cc809c34 100644 --- a/src/librustc_typeck/check/method/mod.rs +++ b/src/librustc_typeck/check/method/mod.rs @@ -213,27 +213,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { segment, ); - let mut needs_mut = false; - if let ty::Ref(region, t_type, mutability) = self_ty.kind { - let trait_type = self.tcx.mk_ref(region, ty::TypeAndMut { - ty: t_type, - mutbl: mutability.invert(), - }); - match self.lookup_probe( - span, - segment.ident, - trait_type, - call_expr, - ProbeScope::TraitsInScope - ) { - Ok(ref new_pick) if *new_pick != pick => { - needs_mut = true; + if result.illegal_sized_bound { + let mut needs_mut = false; + if let ty::Ref(region, t_type, mutability) = self_ty.kind { + let trait_type = self.tcx.mk_ref(region, ty::TypeAndMut { + ty: t_type, + mutbl: mutability.invert(), + }); + // We probe again to see if there might be a borrow mutability discrepancy. + match self.lookup_probe( + span, + segment.ident, + trait_type, + call_expr, + ProbeScope::TraitsInScope + ) { + Ok(ref new_pick) if *new_pick != pick => { + needs_mut = true; + } + _ => {} } - _ => {} } - } - if result.illegal_sized_bound { // We probe again, taking all traits into account (not only those in scope). let candidates = match self.lookup_probe( span, |