Struct ShouldNotBeNull

pub struct ShouldNotBeNull<T: ?Sized>(/* private fields */);

Available on macOS only.

A wrapper type around *mut T to communicate a pointer should not be null without introducing undefined behaviour.

This is necessary for FFI, where, NonNull asks for much stronger guarantees, which we can’t really provide when getting pointers from behind a C interface. ShouldNotBeNull aims for the same usability as NonNull but with panics instead of undefined behaviour when calling methods like as_ref().

Construction is done either directly from C since ShouldNotBeNull is a transparent wrapper or with ShouldNotBeNull::new.

Implementations

impl<T: ?Sized> ShouldNotBeNull<T>

pub fn new(p: *mut T) -> Self

Wraps p in a ShouldNotBeNull.

pub unsafe fn as_ref<'a>(&self) -> &'a T

Calls as_ref() on the inner pointer, panicking if it is null.

Safety

See ptr::as_ref() for the exact safety details.

pub unsafe fn as_opt<'a>(&self) -> Option<&'a T>

Calls as_ref() on the inner pointer.

Safety

See ptr::as_ref() for the exact safety details.

pub const fn as_ptr(self) -> *const T

Access to the inner pointer as a *const

Trait Implementations

impl<T: ?Sized> Clone for ShouldNotBeNull<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: ?Sized> Debug for ShouldNotBeNull<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: ?Sized> PartialEq for ShouldNotBeNull<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: ?Sized> Pointer for ShouldNotBeNull<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: ?Sized> Copy for ShouldNotBeNull<T>

impl<T: ?Sized> Eq for ShouldNotBeNull<T>