auto merge of #11329 : fhahn/rust/unused-cast-lint2, r=alexcrichton

Updates as mentioned in #11135

src/libstd/io/mod.rs

@@ -725,7 +725,7 @@ pub trait Reader {
     ///
     /// `u64`s are 8 bytes long.
     fn read_be_u64(&mut self) -> u64 {
-        self.read_be_uint_n(8) as u64
+        self.read_be_uint_n(8)
     }
 
     /// Reads a big-endian `u32`.
@@ -746,7 +746,7 @@ pub trait Reader {
     ///
     /// `i64`s are 8 bytes long.
     fn read_be_i64(&mut self) -> i64 {
-        self.read_be_int_n(8) as i64
+        self.read_be_int_n(8)
     }
 
     /// Reads a big-endian `i32`.
@@ -785,7 +785,7 @@ pub trait Reader {
     ///
     /// `u64`s are 8 bytes long.
     fn read_le_u64(&mut self) -> u64 {
-        self.read_le_uint_n(8) as u64
+        self.read_le_uint_n(8)
     }
 
     /// Reads a little-endian `u32`.
@@ -806,7 +806,7 @@ pub trait Reader {
     ///
     /// `i64`s are 8 bytes long.
     fn read_le_i64(&mut self) -> i64 {
-        self.read_le_int_n(8) as i64
+        self.read_le_int_n(8)
     }
 
     /// Reads a little-endian `i32`.
@@ -846,7 +846,7 @@ pub trait Reader {
     /// `u8`s are 1 byte.
     fn read_u8(&mut self) -> u8 {
         match self.read_byte() {
-            Some(b) => b as u8,
+            Some(b) => b,
             None => 0
         }
     }

src/libstd/io/net/ip.rs

@@ -153,11 +153,11 @@ impl<'a> Parser<'a> {
             let c = c as u8;
             // assuming radix is either 10 or 16
             if c >= '0' as u8 && c <= '9' as u8 {
-                Some((c - '0' as u8) as u8)
+                Some(c - '0' as u8)
             } else if radix > 10 && c >= 'a' as u8 && c < 'a' as u8 + (radix - 10) {
-                Some((c - 'a' as u8 + 10) as u8)
+                Some(c - 'a' as u8 + 10)
             } else if radix > 10 && c >= 'A' as u8 && c < 'A' as u8 + (radix - 10) {
-                Some((c - 'A' as u8 + 10) as u8)
+                Some(c - 'A' as u8 + 10)
             } else {
                 None
             }

src/libstd/io/stdio.rs

@@ -209,7 +209,7 @@ impl Reader for StdReader {
                 io_error::cond.raise(standard_error(EndOfFile));
                 None
             }
-            Ok(amt) => Some(amt as uint),
+            Ok(amt) => Some(amt),
             Err(e) => {
                 io_error::cond.raise(e);
                 None