Add IntoBuf trait

examples/into_buf.rs

@@ -0,0 +1,17 @@
+extern crate bytes;
+
+use bytes::{Buf, IntoBuf, Bytes};
+
+pub fn dump<T>(data: &T) where
+    for<'a> &'a T: IntoBuf,
+{
+    let mut dst: Vec<u8> = vec![];
+    data.into_buf().copy_to(&mut dst);
+    println!("GOT: {:?}", dst);
+}
+
+pub fn main() {
+    let b = Bytes::from_slice(b"hello world");
+    dump(&b);
+    dump(&b);
+}

src/imp/buf/mod.rs

@@ -363,6 +363,40 @@ pub trait MutBuf {
     }
 }
 
+/*
+ *
+ * ===== IntoBuf =====
+ *
+ */
+
+/// Conversion into a `Buf`
+///
+/// Usually, `IntoBuf` is implemented on references of types and not directly
+/// on the types themselves. For example, `IntoBuf` is implemented for `&'a
+/// Vec<u8>` and not `Vec<u8>` directly.
+pub trait IntoBuf {
+    type Buf: Buf;
+
+    fn into_buf(self) -> Self::Buf;
+}
+
+impl<'a> IntoBuf for &'a [u8] {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    /// Creates a buffer from a value
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(self)
+    }
+}
+
+impl<'a> IntoBuf for &'a Vec<u8> {
+    type Buf = io::Cursor<&'a [u8]>;
+
+    fn into_buf(self) -> Self::Buf {
+        io::Cursor::new(&self[..])
+    }
+}
+
 /*
  *
  * ===== Sink / Source =====

src/imp/bytes/mod.rs

@@ -2,7 +2,7 @@ pub mod rope;
 pub mod seq;
 pub mod small;
 
-use Buf;
+use {Buf, IntoBuf};
 use self::seq::Seq;
 use self::small::Small;
 use self::rope::{Rope, RopeBuf};
@@ -188,6 +188,20 @@ impl cmp::PartialEq<Bytes> for Bytes {
     }
 }
 
+impl<'a> IntoBuf for &'a Bytes {
+    type Buf = BytesBuf<'a>;
+
+    fn into_buf(self) -> Self::Buf {
+        self.buf()
+    }
+}
+
+/*
+ *
+ * ===== BytesBuf =====
+ *
+ */
+
 impl<'a> Buf for BytesBuf<'a> {
     fn remaining(&self) -> usize {
         match self.kind {

src/lib.rs

@@ -10,7 +10,7 @@ mod imp;
 // TODO: delete
 mod alloc;
 
-pub use imp::buf::{Buf, MutBuf};
+pub use imp::buf::{Buf, MutBuf, IntoBuf};
 pub use imp::bytes::Bytes;
 
 pub mod buf {