buffered-reader: New method BufferedReader::as_boxed.

  - This method returns the reader in a box.  The nice thing is that
    we can provide a specialized implementation for
    Box<BufferedReader> that avoids boxing the reader twice.  This
    cleanly addresses the issue worked around in
    9619dffaa756d8cfd6ec691699bd6ae4d59ecfb5.

1 files changed, 13 insertions, 0 deletions

diff --git a/buffered-reader/src/lib.rs b/buffered-reader/src/lib.rs
index f226198e..4661b959 100644
--- a/buffered-reader/src/lib.rs
+++ b/buffered-reader/src/lib.rs
@@ -818,6 +818,13 @@ pub trait BufferedReader<C> : io::Read + fmt::Debug + fmt::Display {
         Ok(at_least_one_byte)
     }
 
+    /// Boxes the reader.
+    fn as_boxed<'a>(self) -> Box<dyn BufferedReader<C> + 'a>
+        where Self: 'a + Sized
+    {
+        Box::new(self)
+    }
+
     /// Returns the underlying reader, if any.
     ///
     /// To allow this to work with `BufferedReader` traits, it is
@@ -963,6 +970,12 @@ impl <'a, C> BufferedReader<C> for Box<dyn BufferedReader<C> + 'a> {
         self.as_ref().get_ref()
     }
 
+    fn as_boxed<'b>(self) -> Box<dyn BufferedReader<C> + 'b>
+        where Self: 'b
+    {
+        self
+    }
+
     fn into_inner<'b>(self: Box<Self>) -> Option<Box<dyn BufferedReader<C> + 'b>>
             where Self: 'b {
         // Strip the outer box.