Struct ValueReadAccess 

pub struct ValueReadAccess<'a, T>
where
    T: 'a + ?Sized,
{ /* private fields */ }

Read guard over a value, obtained from a lifetime or one of its handles.

Derefs to the value and releases the read claim on drop.

Implementations

impl<'a, T> ValueReadAccess<'a, T>

where T: ?Sized,

pub unsafe fn new_raw( data: &'a T, lifetime: LifetimeState, ) -> ValueReadAccess<'a, T>

Builds a guard from parts, without going through the state checks.

Safety

The read claim on lifetime must already be acquired, since dropping this guard releases one. data must be the value that lifetime guards.

impl<'a, T> ValueReadAccess<'a, T>

where T: ?Sized,

pub fn remap<U>( self, f: impl FnOnce(&T) -> Option<&U>, ) -> Result<ValueReadAccess<'a, U>, ValueReadAccess<'a, T>>

Narrows the guard down to a part of the value, for example one field.

Gives the guard back unchanged when f returns None.

Trait Implementations

impl<T> Deref for ValueReadAccess<'_, T>

where T: ?Sized,

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &<ValueReadAccess<'_, T> as Deref>::Target

Dereferences the value.

impl<T> Drop for ValueReadAccess<'_, T>

where T: ?Sized,

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.