Struct Hook 

pub struct Hook<A>(/* private fields */);

An optional callback taking &A. Clones share the same underlying callback.

Implementations

impl<A> Hook<A>

pub const fn none() -> Self

A hook with no callback installed.

pub fn set(&mut self, f: Option<impl Fn(&A) + Send + Sync + 'static>)

Install f, or remove the callback with None.

pub fn is_set(&self) -> bool

Whether a callback is installed.

pub fn fire(&self, arg: &A)

Call the callback, if any.

Trait Implementations

impl<A> Clone for Hook<A>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<A> Debug for Hook<A>

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

Formats the value using the given formatter.

impl<A> Default for Hook<A>

fn default() -> Self

Returns the “default value” for a type.