implement Writer for Vec<u8>

The trait has an obvious, sensible implementation directly on vectors so
the MemWriter wrapper is unnecessary. This will halt the trend towards
providing all of the vector methods on MemWriter along with eliminating
the noise caused by conversions between the two types. It also provides
the useful default Writer methods on Vec<u8>.

After the type is removed and code has been migrated, it would make
sense to add a new implementation of MemWriter with seeking support. The
simple use cases can be covered with vectors alone, and ones with the
need for seeks can use a new MemWriter implementation.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/libstd/io/mem.rs b/src/libstd/io/mem.rs
index 66ae88cfe51..21de6c2013d 100644
--- a/src/libstd/io/mem.rs
+++ b/src/libstd/io/mem.rs
@@ -12,6 +12,8 @@
 
 //! Readers and Writers for in-memory buffers
 
+#![allow(deprecated)]
+
 use cmp::min;
 use option::None;
 use result::{Err, Ok};
@@ -41,6 +43,14 @@ fn combine(seek: SeekStyle, cur: uint, end: uint, offset: i64) -> IoResult<u64>
     }
 }
 
+impl Writer for Vec<u8> {
+    #[inline]
+    fn write(&mut self, buf: &[u8]) -> IoResult<()> {
+        self.push_all(buf);
+        Ok(())
+    }
+}
+
 /// Writes to an owned, growable byte vector
 ///
 /// # Example
@@ -54,6 +64,7 @@ fn combine(seek: SeekStyle, cur: uint, end: uint, offset: i64) -> IoResult<u64>
 ///
 /// assert_eq!(w.unwrap(), vec!(0, 1, 2));
 /// ```
+#[deprecated = "use the Vec<u8> Writer implementation directly"]
 #[deriving(Clone)]
 pub struct MemWriter {
     buf: Vec<u8>,