nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-27 01:04:03 +00:00
Code Issues Packages Projects Releases Wiki Activity

remove a dubious example

Browse Source
This commit is contained in:
Ralf Jung 2022-07-11 11:36:08 -04:00
parent eed5df52f6
commit 1b3870e427
1 changed files with 0 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
library/core/src/intrinsics.rs
View File

@ -2583,38 +2583,6 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
/// }
/// assert_eq!(vec, [0xfefefefe, 0xfefefefe, 0, 0]);
/// ```
///
/// Creating an invalid value:
///
/// ```
/// use std::ptr;
///
/// let mut v = Box::new(0i32);
///
/// unsafe {
/// // Leaks the previously held value by overwriting the `Box<T>` with
/// // a null pointer.
/// ptr::write_bytes(&mut v as *mut Box<i32>, 0, 1);
/// }
///
/// // At this point, using or dropping `v` results in undefined behavior.
/// // drop(v); // ERROR
///
/// // Even leaking `v` "uses" it, and hence is undefined behavior.
/// // mem::forget(v); // ERROR
///
/// // In fact, `v` is invalid according to basic type layout invariants, so *any*
/// // operation touching it is undefined behavior.
/// // let v2 = v; // ERROR
///
/// unsafe {
/// // Let us instead put in a valid value
/// ptr::write(&mut v as *mut Box<i32>, Box::new(42i32));
/// }
///
/// // Now the box is fine
/// assert_eq!(*v, 42);
/// ```
#[doc(alias = "memset")]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_ptr_write", issue = "86302")]