1 files changed, 1 insertions, 60 deletions
diff --git a/library/std/src/io/util/tests.rs b/library/std/src/io/util/tests.rs
index ce5e2c9da..1baa94e64 100644
--- a/library/std/src/io/util/tests.rs
+++ b/library/std/src/io/util/tests.rs
@@ -1,68 +1,9 @@
-use crate::cmp::{max, min};
 use crate::io::prelude::*;
-use crate::io::{
-    copy, empty, repeat, sink, BorrowedBuf, BufWriter, Empty, Repeat, Result, SeekFrom, Sink,
-    DEFAULT_BUF_SIZE,
-};
+use crate::io::{empty, repeat, sink, BorrowedBuf, Empty, Repeat, SeekFrom, Sink};
 
 use crate::mem::MaybeUninit;
 
 #[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 dyn Read, &mut w as &mut dyn Write).unwrap(), 1 << 17);
-}
-
-struct ShortReader {
-    cap: usize,
-    read_size: usize,
-    observed_buffer: usize,
-}
-
-impl Read for ShortReader {
-    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
-        let bytes = min(self.cap, self.read_size);
-        self.cap -= bytes;
-        self.observed_buffer = max(self.observed_buffer, buf.len());
-        Ok(bytes)
-    }
-}
-
-struct WriteObserver {
-    observed_buffer: usize,
-}
-
-impl Write for WriteObserver {
-    fn write(&mut self, buf: &[u8]) -> Result<usize> {
-        self.observed_buffer = max(self.observed_buffer, buf.len());
-        Ok(buf.len())
-    }
-
-    fn flush(&mut self) -> Result<()> {
-        Ok(())
-    }
-}
-
-#[test]
-fn copy_specializes_bufwriter() {
-    let cap = 117 * 1024;
-    let buf_sz = 16 * 1024;
-    let mut r = ShortReader { cap, observed_buffer: 0, read_size: 1337 };
-    let mut w = BufWriter::with_capacity(buf_sz, WriteObserver { observed_buffer: 0 });
-    assert_eq!(
-        copy(&mut r, &mut w).unwrap(),
-        cap as u64,
-        "expected the whole capacity to be copied"
-    );
-    assert_eq!(r.observed_buffer, buf_sz, "expected a large buffer to be provided to the reader");
-    assert!(w.get_mut().observed_buffer > DEFAULT_BUF_SIZE, "expected coalesced writes");
-}
-
-#[test]
 fn sink_sinks() {
     let mut s = sink();
     assert_eq!(s.write(&[]).unwrap(), 0);