pub struct ShouldNotBeNull<T: ?Sized>(/* private fields */);
Available on macOS only.
Expand description

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.

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impl<T: ?Sized> ShouldNotBeNull<T>

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

Wraps p in a ShouldNotBeNull.

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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.

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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.

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

Access to the inner pointer as a *const

Trait Implementations§

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

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fn clone(&self) -> Self

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl<T: ?Sized> Debug for ShouldNotBeNull<T>

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

Formats the value using the given formatter. Read more
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impl<T: ?Sized> PartialEq for ShouldNotBeNull<T>

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

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<T: ?Sized> Pointer for ShouldNotBeNull<T>

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

Formats the value using the given formatter.
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impl<T: ?Sized> Copy for ShouldNotBeNull<T>

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

Auto Trait Implementations§

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impl<T: ?Sized> RefUnwindSafe for ShouldNotBeNull<T>where T: RefUnwindSafe,

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impl<T> !Send for ShouldNotBeNull<T>

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impl<T> !Sync for ShouldNotBeNull<T>

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

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impl<T: ?Sized> UnwindSafe for ShouldNotBeNull<T>where T: RefUnwindSafe,

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for Twhere T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> AutoreleaseSafe for Twhere T: ?Sized,