rustc_driver: unbox closures used in let bindings

Author: Jorge Aparicio

src/librustc_driver/lib.rs

@@ -278,7 +278,7 @@ Available lint options:
     let max_name_len = plugin.iter().chain(builtin.iter())
         .map(|&s| s.name.width(true))
         .max().unwrap_or(0);
-    let padded = |x: &str| {
+    let padded = |&: x: &str| {
         let mut s = repeat(" ").take(max_name_len - x.chars().count())
                                .collect::<String>();
         s.push_str(x);
@@ -289,7 +289,7 @@ Available lint options:
     println!("    {}  {:7.7}  {}", padded("name"), "default", "meaning");
     println!("    {}  {:7.7}  {}", padded("----"), "-------", "-------");
 
-    let print_lints = |lints: Vec<&Lint>| {
+    let print_lints = |&: lints: Vec<&Lint>| {
         for lint in lints.into_iter() {
             let name = lint.name_lower().replace("_", "-");
             println!("    {}  {:7.7}  {}",
@@ -305,7 +305,7 @@ Available lint options:
     let max_name_len = plugin_groups.iter().chain(builtin_groups.iter())
         .map(|&(s, _)| s.width(true))
         .max().unwrap_or(0);
-    let padded = |x: &str| {
+    let padded = |&: x: &str| {
         let mut s = repeat(" ").take(max_name_len - x.chars().count())
                                .collect::<String>();
         s.push_str(x);
@@ -316,7 +316,7 @@ Available lint options:
     println!("    {}  {}", padded("name"), "sub-lints");
     println!("    {}  {}", padded("----"), "---------");
 
-    let print_lint_groups = |lints: Vec<(&'static str, Vec<lint::LintId>)>| {
+    let print_lint_groups = |&: lints: Vec<(&'static str, Vec<lint::LintId>)>| {
         for (name, to) in lints.into_iter() {
             let name = name.chars().map(|x| x.to_lowercase())
                            .collect::<String>().replace("_", "-");

src/librustc_driver/pretty.rs

@@ -301,7 +301,7 @@ fn gather_flowgraph_variants(sess: &Session) -> Vec<borrowck_dot::Variant> {
     let print_moves   = config::FLOWGRAPH_PRINT_MOVES;
     let print_assigns = config::FLOWGRAPH_PRINT_ASSIGNS;
     let print_all     = config::FLOWGRAPH_PRINT_ALL;
-    let opt = |print_which| sess.debugging_opt(print_which);
+    let opt = |&: print_which| sess.debugging_opt(print_which);
     let mut variants = Vec::new();
     if opt(print_all) || opt(print_loans) {
         variants.push(borrowck_dot::Loans);
@@ -365,7 +365,7 @@ impl UserIdentifiedItem {
     }
 
     fn to_one_node_id(self, user_option: &str, sess: &Session, map: &ast_map::Map) -> ast::NodeId {
-        let fail_because = |is_wrong_because| -> ast::NodeId {
+        let fail_because = |&: is_wrong_because| -> ast::NodeId {
             let message =
                 format!("{} needs NodeId (int) or unique \
                          path suffix (b::c::d); got {}, which {}",