let b_ty = &b_subst.types[i];
let variance = variances.map_or(ty::Invariant, |v| v.types[i]);
relation.relate_with_variance(variance, a_ty, b_ty)
- }).collect()?;
+ }).collect::<Result<_, _>>()?;
let regions = a_subst.regions.iter().enumerate().map(|(i, a_r)| {
let b_r = &b_subst.regions[i];
let variance = variances.map_or(ty::Invariant, |v| v.regions[i]);
relation.relate_with_variance(variance, a_r, b_r)
- }).collect()?;
+ }).collect::<Result<_, _>>()?;
Ok(Substs::new(tcx, types, regions))
}