Opt for .cloned() over .map(|x| x.clone()) etc.

10 files changed, 20 insertions, 22 deletions

diff --git a/src/libsyntax/ast_map/mod.rs b/src/libsyntax/ast_map/mod.rs
index 5535e5911e0..6535705388d 100644
--- a/src/libsyntax/ast_map/mod.rs
+++ b/src/libsyntax/ast_map/mod.rs
@@ -251,7 +251,7 @@ impl<'ast> Map<'ast> {
     }
 
     fn find_entry(&self, id: NodeId) -> Option<MapEntry<'ast>> {
-        self.map.borrow().get(id as usize).map(|e| *e)
+        self.map.borrow().get(id as usize).cloned()
     }
 
     pub fn krate(&self) -> &'ast Crate {
diff --git a/src/libsyntax/diagnostics/registry.rs b/src/libsyntax/diagnostics/registry.rs
index 62d48189c43..968fceb6f6f 100644
--- a/src/libsyntax/diagnostics/registry.rs
+++ b/src/libsyntax/diagnostics/registry.rs
@@ -21,6 +21,6 @@ impl Registry {
     }
 
     pub fn find_description(&self, code: &str) -> Option<&'static str> {
-        self.descriptions.get(code).map(|desc| *desc)
+        self.descriptions.get(code).cloned()
     }
 }
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 083039995ee..8fdc3c8447a 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -639,7 +639,7 @@ impl<'a> ExtCtxt<'a> {
     pub fn mod_path(&self) -> Vec<ast::Ident> {
         let mut v = Vec::new();
         v.push(token::str_to_ident(&self.ecfg.crate_name[]));
-        v.extend(self.mod_path.iter().map(|a| *a));
+        v.extend(self.mod_path.iter().cloned());
         return v;
     }
     pub fn bt_push(&mut self, ei: ExpnInfo) {
diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
index f878cb5ca8b..8b4eaab386d 100644
--- a/src/libsyntax/ext/deriving/generic/mod.rs
+++ b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -367,7 +367,7 @@ impl<'a> TraitDef<'a> {
                 "allow" | "warn" | "deny" | "forbid" => true,
                 _ => false,
             }
-        }).map(|a| a.clone()));
+        }).cloned());
         push(P(ast::Item {
             attrs: attrs,
             ..(*newitem).clone()
@@ -410,7 +410,7 @@ impl<'a> TraitDef<'a> {
         let mut ty_params = ty_params.into_vec();
 
         // Copy the lifetimes
-        lifetimes.extend(generics.lifetimes.iter().map(|l| (*l).clone()));
+        lifetimes.extend(generics.lifetimes.iter().cloned());
 
         // Create the type parameters.
         ty_params.extend(generics.ty_params.iter().map(|ty_param| {
@@ -445,14 +445,14 @@ impl<'a> TraitDef<'a> {
                         span: self.span,
                         bound_lifetimes: wb.bound_lifetimes.clone(),
                         bounded_ty: wb.bounded_ty.clone(),
-                        bounds: OwnedSlice::from_vec(wb.bounds.iter().map(|b| b.clone()).collect())
+                        bounds: OwnedSlice::from_vec(wb.bounds.iter().cloned().collect())
                     })
                 }
                 ast::WherePredicate::RegionPredicate(ref rb) => {
                     ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
                         span: self.span,
                         lifetime: rb.lifetime,
-                        bounds: rb.bounds.iter().map(|b| b.clone()).collect()
+                        bounds: rb.bounds.iter().cloned().collect()
                     })
                 }
                 ast::WherePredicate::EqPredicate(ref we) => {
@@ -500,7 +500,7 @@ impl<'a> TraitDef<'a> {
         let opt_trait_ref = Some(trait_ref);
         let ident = ast_util::impl_pretty_name(&opt_trait_ref, &*self_type);
         let mut a = vec![attr];
-        a.extend(self.attributes.iter().map(|a| a.clone()));
+        a.extend(self.attributes.iter().cloned());
         cx.item(
             self.span,
             ident,
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 7a3a3562bdf..d1dee115b6b 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -179,7 +179,7 @@ pub fn expand_include_bytes(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             return DummyResult::expr(sp);
         }
         Ok(bytes) => {
-            let bytes = bytes.iter().map(|x| *x).collect();
+            let bytes = bytes.iter().cloned().collect();
             base::MacExpr::new(cx.expr_lit(sp, ast::LitBinary(Rc::new(bytes))))
         }
     }
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index d752e34c112..a3224c25d09 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -283,7 +283,7 @@ pub fn parse(sess: &ParseSess,
              -> ParseResult {
     let mut cur_eis = Vec::new();
     cur_eis.push(initial_matcher_pos(Rc::new(ms.iter()
-                                                .map(|x| (*x).clone())
+                                                .cloned()
                                                 .collect()),
                                      None,
                                      rdr.peek().sp.lo));
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index f322cf8bad0..1a6cf7d07f1 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -159,7 +159,7 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
                                                       None,
                                                       None,
                                                       arg.iter()
-                                                         .map(|x| (*x).clone())
+                                                         .cloned()
                                                          .collect(),
                                                       true);
             match parse(cx.parse_sess(), cx.cfg(), arg_rdr, lhs_tt) {
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index b17fc7fe82e..c0823e04288 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -61,7 +61,7 @@ pub fn doc_comment_style(comment: &str) -> ast::AttrStyle {
 
 pub fn strip_doc_comment_decoration(comment: &str) -> String {
     /// remove whitespace-only lines from the start/end of lines
-    fn vertical_trim(lines: Vec<String> ) -> Vec<String> {
+    fn vertical_trim(lines: Vec<String>) -> Vec<String> {
         let mut i = 0;
         let mut j = lines.len();
         // first line of all-stars should be omitted
@@ -82,7 +82,7 @@ pub fn strip_doc_comment_decoration(comment: &str) -> String {
         while j > i && lines[j - 1].trim().is_empty() {
             j -= 1;
         }
-        return lines[i..j].iter().map(|x| (*x).clone()).collect();
+        lines[i..j].iter().cloned().collect()
     }
 
     /// remove a "[ \t]*\*" block from each line, if possible
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 407740e580d..f14cd524776 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -240,9 +240,8 @@ macro_rules! maybe_whole {
 
 fn maybe_append(mut lhs: Vec<Attribute>, rhs: Option<Vec<Attribute>>)
                 -> Vec<Attribute> {
-    match rhs {
-        Some(ref attrs) => lhs.extend(attrs.iter().map(|a| a.clone())),
-        None => {}
+    if let Some(ref attrs) = rhs {
+        lhs.extend(attrs.iter().cloned())
     }
     lhs
 }
@@ -467,7 +466,7 @@ impl<'a> Parser<'a> {
         debug!("commit_expr {:?}", e);
         if let ExprPath(..) = e.node {
             // might be unit-struct construction; check for recoverableinput error.
-            let mut expected = edible.iter().map(|x| x.clone()).collect::<Vec<_>>();
+            let mut expected = edible.iter().cloned().collect::<Vec<_>>();
             expected.push_all(inedible);
             self.check_for_erroneous_unit_struct_expecting(&expected[]);
         }
@@ -485,7 +484,7 @@ impl<'a> Parser<'a> {
         if self.last_token
                .as_ref()
                .map_or(false, |t| t.is_ident() || t.is_path()) {
-            let mut expected = edible.iter().map(|x| x.clone()).collect::<Vec<_>>();
+            let mut expected = edible.iter().cloned().collect::<Vec<_>>();
             expected.push_all(&inedible[]);
             self.check_for_erroneous_unit_struct_expecting(
                 &expected[]);
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 583095e1574..8f1acde1546 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -983,15 +983,14 @@ impl<'a> State<'a> {
                 try!(self.word_nbsp("trait"));
                 try!(self.print_ident(item.ident));
                 try!(self.print_generics(generics));
-                let bounds: Vec<_> = bounds.iter().map(|b| b.clone()).collect();
                 let mut real_bounds = Vec::with_capacity(bounds.len());
-                for b in bounds {
-                    if let TraitTyParamBound(ref ptr, ast::TraitBoundModifier::Maybe) = b {
+                for b in bounds.iter() {
+                    if let TraitTyParamBound(ref ptr, ast::TraitBoundModifier::Maybe) = *b {
                         try!(space(&mut self.s));
                         try!(self.word_space("for ?"));
                         try!(self.print_trait_ref(&ptr.trait_ref));
                     } else {
-                        real_bounds.push(b);
+                        real_bounds.push(b.clone());
                     }
                 }
                 try!(self.print_bounds(":", &real_bounds[]));