diff options
Diffstat (limited to 'src/test/ui/methods/method-mut-self-modifies-mut-slice-lvalue.rs')
-rw-r--r-- | src/test/ui/methods/method-mut-self-modifies-mut-slice-lvalue.rs | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/src/test/ui/methods/method-mut-self-modifies-mut-slice-lvalue.rs b/src/test/ui/methods/method-mut-self-modifies-mut-slice-lvalue.rs deleted file mode 100644 index daff037b2..000000000 --- a/src/test/ui/methods/method-mut-self-modifies-mut-slice-lvalue.rs +++ /dev/null @@ -1,44 +0,0 @@ -// run-pass -// Test that an `&mut self` method, when invoked on a place whose -// type is `&mut [u8]`, passes in a pointer to the place and not a -// temporary. Issue #19147. - -use std::slice; -use std::cmp; - -trait MyWriter { - fn my_write(&mut self, buf: &[u8]) -> Result<(), ()>; -} - -impl<'a> MyWriter for &'a mut [u8] { - fn my_write(&mut self, buf: &[u8]) -> Result<(), ()> { - let amt = cmp::min(self.len(), buf.len()); - self[..amt].clone_from_slice(&buf[..amt]); - - let write_len = buf.len(); - unsafe { - *self = slice::from_raw_parts_mut( - self.as_mut_ptr().add(write_len), - self.len() - write_len - ); - } - - Ok(()) - } -} - -fn main() { - let mut buf = [0; 6]; - - { - let mut writer: &mut [_] = &mut buf; - writer.my_write(&[0, 1, 2]).unwrap(); - writer.my_write(&[3, 4, 5]).unwrap(); - } - - // If `my_write` is not modifying `buf` in place, then we will - // wind up with `[3, 4, 5, 0, 0, 0]` because the first call to - // `my_write()` doesn't update the starting point for the write. - - assert_eq!(buf, [0, 1, 2, 3, 4, 5]); -} |