ugly, but works!

Author: qmx

src/librustc_mir/transform/inline.rs

@@ -88,12 +88,22 @@ impl<'a, 'tcx> Inliner<'a, 'tcx> {
                 if let TerminatorKind::Call {
                     func: Operand::Constant(ref f), .. } = terminator.kind {
                     if let ty::TyFnDef(callee_def_id, substs) = f.ty.sty {
-                        callsites.push_back(CallSite {
-                            callee: callee_def_id,
-                            substs,
-                            bb,
-                            location: terminator.source_info
-                        });
+                        let should_inline = match self.tcx.opt_associated_item(callee_def_id) {
+                            Some(item) => match item.container {
+                               ty::AssociatedItemContainer::ImplContainer(_) => true,
+                               ty::AssociatedItemContainer::TraitContainer(_) => false,
+                            },
+                            None => true
+                        };
+
+                        if should_inline {
+                            callsites.push_back(CallSite {
+                                callee: callee_def_id,
+                                substs,
+                                bb,
+                                location: terminator.source_info
+                            });
+                        }
                     }
                 }
             }