let ty = fcx.tcx.erase_regions(ty);
let expr_ty = fcx.resolve_vars_if_possible(self.expr_ty);
let expr_ty = fcx.tcx.erase_regions(expr_ty);
- let ty_params = fcx.tcx.mk_substs_trait(expr_ty, &[]);
+ let ty_params = fcx.tcx.mk_substs(std::iter::once(ty::GenericArg::from(expr_ty)));
if fcx
.infcx
.type_implements_trait(from_trait, ty, ty_params, fcx.param_env)