diff options
| -rw-r--r-- | library/core/src/ptr/const_ptr.rs | 48 | ||||
| -rw-r--r-- | library/core/src/ptr/mut_ptr.rs | 49 |
2 files changed, 97 insertions, 0 deletions
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index 344b483662a..03f17e0697c 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -48,6 +48,54 @@ impl<T: ?Sized> *const T { self as _ } + /// Casts a pointer to its raw bits. + /// + /// This is equivalent to `as usize`, but is more specific to enhance readability. + /// The inverse method is [`Self::from_bits`]. + /// + /// In particular, `*p as usize` and `p as usize` will both compile for + /// pointers to numeric types but do very different things, so using this + /// helps emphasize that reading the bits was intentional. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_to_from_bits)] + /// let array = [13, 42]; + /// let p0: *const i32 = &array[0]; + /// assert_eq!(<*const _>::from_bits(p0.to_bits()), p0); + /// let p1: *const i32 = &array[1]; + /// assert_eq!(p1.to_bits() - p0.to_bits(), 4); + /// ``` + #[unstable(feature = "ptr_to_from_bits", issue = "91126")] + pub fn to_bits(self) -> usize + where + T: Sized, + { + self as usize + } + + /// Creates a pointer from its raw bits. + /// + /// This is equivalent to `as *const T`, but is more specific to enhance readability. + /// The inverse method is [`Self::to_bits`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_to_from_bits)] + /// use std::ptr::NonNull; + /// let dangling: *const u8 = NonNull::dangling().as_ptr(); + /// assert_eq!(<*const u8>::from_bits(1), dangling); + /// ``` + #[unstable(feature = "ptr_to_from_bits", issue = "91126")] + pub fn from_bits(bits: usize) -> Self + where + T: Sized, + { + bits as Self + } + /// Decompose a (possibly wide) pointer into its address and metadata components. /// /// The pointer can be later reconstructed with [`from_raw_parts`]. diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index f3b2bdfefe5..5a5ce5ee121 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -47,6 +47,55 @@ impl<T: ?Sized> *mut T { self as _ } + /// Casts a pointer to its raw bits. + /// + /// This is equivalent to `as usize`, but is more specific to enhance readability. + /// The inverse method is [`Self::from_bits`]. + /// + /// In particular, `*p as usize` and `p as usize` will both compile for + /// pointers to numeric types but do very different things, so using this + /// helps emphasize that reading the bits was intentional. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_to_from_bits)] + /// let mut array = [13, 42]; + /// let mut it = array.iter_mut(); + /// let p0: *mut i32 = it.next().unwrap(); + /// assert_eq!(<*mut _>::from_bits(p0.to_bits()), p0); + /// let p1: *mut i32 = it.next().unwrap(); + /// assert_eq!(p1.to_bits() - p0.to_bits(), 4); + /// ``` + #[unstable(feature = "ptr_to_from_bits", issue = "91126")] + pub fn to_bits(self) -> usize + where + T: Sized, + { + self as usize + } + + /// Creates a pointer from its raw bits. + /// + /// This is equivalent to `as *mut T`, but is more specific to enhance readability. + /// The inverse method is [`Self::to_bits`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(ptr_to_from_bits)] + /// use std::ptr::NonNull; + /// let dangling: *mut u8 = NonNull::dangling().as_ptr(); + /// assert_eq!(<*mut u8>::from_bits(1), dangling); + /// ``` + #[unstable(feature = "ptr_to_from_bits", issue = "91126")] + pub fn from_bits(bits: usize) -> Self + where + T: Sized, + { + bits as Self + } + /// Decompose a (possibly wide) pointer into its address and metadata components. /// /// The pointer can be later reconstructed with [`from_raw_parts_mut`]. |