7 files changed, 12 insertions, 11 deletions
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 1abe8d0a3c1..6a00fff1860 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -284,7 +284,7 @@ pub const COMMAND_LINE_EXPN: ExpnId = ExpnId(-2);
 
 impl ExpnId {
     pub fn from_llvm_cookie(cookie: c_uint) -> ExpnId {
-        ExpnId(cookie as u32)
+        ExpnId(cookie)
     }
 
     pub fn to_llvm_cookie(self) -> i32 {
@@ -376,7 +376,7 @@ impl Encodable for FileMap {
                         match bytes_per_diff {
                             1 => for diff in diff_iter { try! { (diff.0 as u8).encode(s) } },
                             2 => for diff in diff_iter { try! { (diff.0 as u16).encode(s) } },
-                            4 => for diff in diff_iter { try! { (diff.0 as u32).encode(s) } },
+                            4 => for diff in diff_iter { try! { diff.0.encode(s) } },
                             _ => unreachable!()
                         }
                     }
@@ -650,7 +650,7 @@ impl CodeMap {
         let lo = self.lookup_char_pos(sp.lo);
         let hi = self.lookup_char_pos(sp.hi);
         let mut lines = Vec::new();
-        for i in lo.line - 1..hi.line as usize {
+        for i in lo.line - 1..hi.line {
             lines.push(i);
         };
         FileLines {file: lo.file, lines: lines}
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 35449bde0b2..b679456b353 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -264,7 +264,7 @@ macro_rules! make_MacEager {
                     box MacEager {
                         $fld: Some(v),
                         ..Default::default()
-                    } as Box<MacResult>
+                    }
                 }
             )*
         }
@@ -330,7 +330,7 @@ impl DummyResult {
     /// Use this as a return value after hitting any errors and
     /// calling `span_err`.
     pub fn any(sp: Span) -> Box<MacResult+'static> {
-        box DummyResult { expr_only: false, span: sp } as Box<MacResult+'static>
+        box DummyResult { expr_only: false, span: sp }
     }
 
     /// Create a default MacResult that can only be an expression.
@@ -339,7 +339,7 @@ impl DummyResult {
     /// if an error is encountered internally, the user will receive
     /// an error that they also used it in the wrong place.
     pub fn expr(sp: Span) -> Box<MacResult+'static> {
-        box DummyResult { expr_only: true, span: sp } as Box<MacResult+'static>
+        box DummyResult { expr_only: true, span: sp }
     }
 
     /// A plain dummy expression.
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index c11ffe66e6c..a25a6451918 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -262,6 +262,7 @@ pub mod rt {
         (unsigned, $t:ty, $tag:expr) => (
             impl ToSource for $t {
                 fn to_source(&self) -> String {
+                    #![allow(trivial_numeric_casts)]
                     let lit = ast::LitInt(*self as u64, ast::UnsignedIntLit($tag));
                     pprust::lit_to_string(&dummy_spanned(lit))
                 }
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 5940b791843..1e53db60301 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -169,7 +169,7 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
                 // Weird, but useful for X-macros.
                 return box ParserAnyMacro {
                     parser: RefCell::new(p),
-                } as Box<MacResult+'cx>
+                }
               }
               Failure(sp, ref msg) => if sp.lo >= best_fail_spot.lo {
                 best_fail_spot = sp;
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index e0953a8ace6..0843713681b 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -758,7 +758,7 @@ impl<'a> StringReader<'a> {
                 self.err_span_char(self.last_pos, self.pos,
                               "illegal character in numeric character escape", c);
                 0
-            }) as u32;
+            });
             self.bump();
         }
 
@@ -887,7 +887,7 @@ impl<'a> StringReader<'a> {
                     self.fatal_span_char(self.last_pos, self.pos,
                                    "illegal character in unicode escape", c);
                 }
-            }) as u32;
+            });
             self.bump();
             count += 1;
         }
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index fe259d0bf78..220ea30256e 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -865,7 +865,7 @@ impl<'a> Parser<'a> {
         } else {
             // Avoid token copies with `replace`.
             let buffer_start = self.buffer_start as usize;
-            let next_index = (buffer_start + 1) & 3 as usize;
+            let next_index = (buffer_start + 1) & 3;
             self.buffer_start = next_index as isize;
 
             let placeholder = TokenAndSpan {
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index f6213b7db40..2bc3fc1017a 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2836,7 +2836,7 @@ impl<'a> State<'a> {
             ast::LitBinary(ref v) => {
                 let mut escaped: String = String::new();
                 for &ch in &**v {
-                    escaped.extend(ascii::escape_default(ch as u8)
+                    escaped.extend(ascii::escape_default(ch)
                                          .map(|c| c as char));
                 }
                 word(&mut self.s, &format!("b\"{}\"", escaped))