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ptr::invalid is not the same as a cast #9

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Jun 8, 2022
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ptr::invalid is not the same as a cast #9

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12 changes: 6 additions & 6 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -363,16 +363,16 @@

/// Creates an invalid pointer with the given address.
///
/// This is *currently* equivalent to `addr as *const T` but it expresses the intended semantic
/// more clearly, and may become important under future memory models.
/// This is different from `addr as *const T`, which creates a pointer that picks up a previously
/// exposed provenance. See [`from_exposed_addr`] for more details on that operation.
///
/// The module's top-level documentation discusses the precise meaning of an "invalid"
/// pointer but essentially this expresses that the pointer is not associated
/// with any actual allocation and is little more than a usize address in disguise.
///
/// This pointer will have no provenance associated with it and is therefore
/// UB to read/write/offset. This mostly exists to facilitate things
/// like ptr::null and NonNull::dangling which make invalid pointers.
/// like `ptr::null` and `NonNull::dangling` which make invalid pointers.
///
/// (Standard "Zero-Sized-Types get to cheat and lie" caveats apply, although it
/// may be desirable to give them their own API just to make that 100% clear.)
Expand All @@ -396,16 +396,16 @@ pub const fn invalid<T>(addr: usize) -> *const T {

/// Creates an invalid mutable pointer with the given address.
///
/// This is *currently* equivalent to `addr as *mut T` but it expresses the intended semantic
/// more clearly, and may become important under future memory models.
/// This is different from `addr as *mut T`, which creates a pointer that picks up a previously
/// exposed provenance. See [`from_exposed_addr_mut`] for more details on that operation.
///
/// The module's top-level documentation discusses the precise meaning of an "invalid"
/// pointer but essentially this expresses that the pointer is not associated
/// with any actual allocation and is little more than a usize address in disguise.
///
/// This pointer will have no provenance associated with it and is therefore
/// UB to read/write/offset. This mostly exists to facilitate things
/// like ptr::null and NonNull::dangling which make invalid pointers.
/// like `ptr::null` and `NonNull::dangling` which make invalid pointers.
///
/// (Standard "Zero-Sized-Types get to cheat and lie" caveats apply, although it
/// may be desirable to give them their own API just to make that 100% clear.)
Expand Down