diff options
| -rw-r--r-- | src/libstd/io/util.rs | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/libstd/io/util.rs b/src/libstd/io/util.rs index 6e651464c74..39833cd2cc7 100644 --- a/src/libstd/io/util.rs +++ b/src/libstd/io/util.rs @@ -45,7 +45,9 @@ use io::{self, Read, Write, ErrorKind, BufRead}; /// # } /// ``` #[stable(feature = "rust1", since = "1.0.0")] -pub fn copy<R: Read, W: Write>(reader: &mut R, writer: &mut W) -> io::Result<u64> { +pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64> + where R: Read, W: Write +{ let mut buf = [0; super::DEFAULT_BUF_SIZE]; let mut written = 0; loop { @@ -153,7 +155,17 @@ mod tests { use prelude::v1::*; use io::prelude::*; - use io::{sink, empty, repeat}; + use io::{copy, sink, empty, repeat}; + + #[test] + fn copy_copies() { + let mut r = repeat(0).take(4); + let mut w = sink(); + assert_eq!(copy(&mut r, &mut w).unwrap(), 4); + + let mut r = repeat(0).take(1 << 17); + assert_eq!(copy(&mut r as &mut Read, &mut w as &mut Write).unwrap(), 1 << 17); + } #[test] fn sink_sinks() { |