diff --git a/src/interpreter.rs b/src/interpreter.rs
index 91682207ed6..0b4aab71b61 100644
--- a/src/interpreter.rs
+++ b/src/interpreter.rs
@@ -830,7 +830,7 @@ impl<'a, 'tcx: 'a, 'arena> Interpreter<'a, 'tcx, 'arena> {
 
                     Index(ref operand) => {
                         let elem_size = match base_ty.sty {
-                            ty::TyArray(elem_ty, _) => self.type_size(elem_ty),
+                            ty::TyArray(elem_ty, _) |
                             ty::TySlice(elem_ty) => self.type_size(elem_ty),
                             _ => panic!("indexing expected an array or slice, got {:?}", base_ty),
                         };
@@ -1109,11 +1109,9 @@ impl<'a, 'tcx: 'a, 'arena> Interpreter<'a, 'tcx, 'arena> {
         let vtable = selection.map(|predicate| {
             fulfill_cx.register_predicate_obligation(&infcx, predicate);
         });
-        let vtable = infer::drain_fulfillment_cx_or_panic(
+        infer::drain_fulfillment_cx_or_panic(
             DUMMY_SP, &infcx, &mut fulfill_cx, &vtable
-        );
-
-        vtable
+        )
     }
 
     /// Trait method, which has to be resolved to an impl method.
@@ -1166,7 +1164,7 @@ impl<'a, 'tcx: 'a, 'arena> Interpreter<'a, 'tcx, 'arena> {
     }
 }
 
-fn pointee_type<'tcx>(ptr_ty: ty::Ty<'tcx>) -> Option<ty::Ty<'tcx>> {
+fn pointee_type(ptr_ty: ty::Ty) -> Option<ty::Ty> {
     match ptr_ty.sty {
         ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
         ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
diff --git a/src/memory.rs b/src/memory.rs
index 14aa4f9d799..285c3554b64 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -47,7 +47,7 @@ pub struct FieldRepr {
 impl Repr {
     pub fn size(&self) -> usize {
         match *self {
-            Repr::Primitive { size } => size,
+            Repr::Primitive { size } |
             Repr::Aggregate { size, .. } => size,
             Repr::Array { elem_size, length } => elem_size * length,
         }
@@ -406,7 +406,7 @@ impl Memory {
     fn clear_relocations(&mut self, ptr: Pointer, size: usize) -> EvalResult<()> {
         // Find all relocations overlapping the given range.
         let keys: Vec<_> = try!(self.relocations(ptr, size)).map(|(&k, _)| k).collect();
-        if keys.len() == 0 { return Ok(()); }
+        if keys.is_empty() { return Ok(()); }
 
         // Find the start and end of the given range and its outermost relocations.
         let start = ptr.offset;