diff --git a/src/librustc/middle/borrowck/mod.rs b/src/librustc/middle/borrowck/mod.rs
index 5504393e7c27..1011a001aaf7 100644
--- a/src/librustc/middle/borrowck/mod.rs
+++ b/src/librustc/middle/borrowck/mod.rs
@@ -25,7 +25,6 @@ use std::cell::{Cell, RefCell};
 use std::ops::{BitOr, BitAnd};
 use std::rc::Rc;
 use std::strbuf::StrBuf;
-use collections::HashMap;
 use syntax::ast;
 use syntax::ast_map;
 use syntax::ast_util;
diff --git a/src/librustc/middle/trans/debuginfo.rs b/src/librustc/middle/trans/debuginfo.rs
index 27a97af61089..0c7d36e0dbed 100644
--- a/src/librustc/middle/trans/debuginfo.rs
+++ b/src/librustc/middle/trans/debuginfo.rs
@@ -640,7 +640,7 @@ pub fn create_function_debug_context(cx: &CrateContext,
                 }
             }
         }
-        ast_map::NodeMethod(method) => {
+        ast_map::NodeMethod(ref method) => {
             (method.ident,
              method.decl,
              &method.generics,
@@ -667,9 +667,9 @@ pub fn create_function_debug_context(cx: &CrateContext,
                         "create_function_debug_context: expected an expr_fn_block here")
             }
         }
-        ast_map::NodeTraitMethod(trait_method) => {
-            match *trait_method {
-                ast::Provided(method) => {
+        ast_map::NodeTraitMethod(ref trait_method) => {
+            match **trait_method {
+                ast::Provided(ref method) => {
                     (method.ident,
                      method.decl,
                      &method.generics,
diff --git a/src/librustc/middle/typeck/infer/error_reporting.rs b/src/librustc/middle/typeck/infer/error_reporting.rs
index bb9c6a87babd..df102b8aadf3 100644
--- a/src/librustc/middle/typeck/infer/error_reporting.rs
+++ b/src/librustc/middle/typeck/infer/error_reporting.rs
@@ -674,14 +674,16 @@ impl<'a> ErrorReporting for InferCtxt<'a> {
         let parent = self.tcx.map.get_parent(scope_id);
         let parent_node = self.tcx.map.find(parent);
         let node_inner = match parent_node {
-            Some(node) => match node {
-                ast_map::NodeItem(item) => match item.node {
-                    ast::ItemFn(ref fn_decl, ref pur, _, ref gen, _) => {
-                        Some((fn_decl, gen, *pur, item.ident, None, item.span))
-                    },
-                    _ => None
-                },
-                ast_map::NodeMethod(m) => {
+            Some(ref node) => match *node {
+                ast_map::NodeItem(ref item) => {
+                    match item.node {
+                        ast::ItemFn(ref fn_decl, ref pur, _, ref gen, _) => {
+                            Some((fn_decl, gen, *pur, item.ident, None, item.span))
+                        },
+                        _ => None
+                    }
+                }
+                ast_map::NodeMethod(ref m) => {
                     Some((&m.decl, &m.generics, m.fn_style,
                           m.ident, Some(m.explicit_self.node), m.span))
                 },