Struct manually_boxed::NoAliasSingleton

#[non_exhaustive]
pub struct NoAliasSingleton {}

Singleton, used for compile-time alias checking

You’ll need one owned one of these, from NoAliasSingleton::init().

Typically, instead of passing &mut NoAliasSingleton to your own sub-functions, you’ll pass TokenMut (or TokenRef, which can be obtained (and copied) with IsTokenRef::token_ref and IsTokenMut::token_mut.

Those token types are zero-sized types, so they incur no runtime cost, even if the compiler can’t figure out that they aren’t ever used.

(NoAliasSingleton is a ZST too, but of course &mut NoAliasSingleton isn’t.)

Implementations

impl NoAliasSingleton

pub unsafe fn init() -> Self

Initialises, by creating the singleton for alias checking

SAFETY

There must be only one NoAliasSingleton used with each Ptr.

That is, it is unsound to use the same Ptr (or any copy of it) with TokenMutes derived from two (or more) different NoAliasSingletons.

The easiest way to do this is to have only one NoAliasSingleton.

If this rule is violated, borrow and borrow_mut can be instant-UB.

Trait Implementations

impl Debug for NoAliasSingleton

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

Formats the value using the given formatter.

impl<'a> IsTokenMut<'a> for &'a mut NoAliasSingleton

fn token_mut<'r>(self) -> TokenMut<'r>

where 'a: 'r,

Obtains a new ZST token from something that might be a real object.

fn as_mut<'r, 's: 'r>(&'s mut self) -> TokenMut<'r>

where 'a: 'r,

Obtains a new ZST token from a borrow that might be of a real object.

fn multi_static<'r>(self) -> MultiStatic<'r, ()>

where 'a: 'r,

Borrows from a small, fixed, number of multiple Ptr

fn multi_dynamic<'r>(self) -> MultiDynamic<'r>

where 'a: 'r,

Borrows from an unknown number of Ptr with dynamic runtime checking

impl<'a> IsTokenRef<'a> for &'a NoAliasSingleton

fn token_ref(self) -> TokenRef<'a>

Obtains a new ZST token from something that might be a real object.

impl<'a> IsTokenRef<'a> for &'a mut NoAliasSingleton

fn token_ref(self) -> TokenRef<'a>

Obtains a new ZST token from something that might be a real object.