pub struct NoHandler;Expand description
Type-level “no callback” sentinel.
Pass Handlers::NONE (which is None::<&Handler<NoHandler>>) to any
callback-accepting method to leave that callback unset. NoHandler implements
every generated callback trait, so the method’s callback generic is inferred as
NoHandler without a per-callback helper or turbofish — including methods with
several callback parameters (e.g. async_add_subscription’s image handlers).
Its callback methods are unreachable: the C side is handed a null callback +
null clientd, so they can never fire.
Auto Trait Implementations§
impl Freeze for NoHandler
impl RefUnwindSafe for NoHandler
impl Send for NoHandler
impl Sync for NoHandler
impl Unpin for NoHandler
impl UnsafeUnpin for NoHandler
impl UnwindSafe for NoHandler
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
Converts
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
Converts
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more