Struct FireHandle 

pub struct FireHandle { /* private fields */ }

A handle to a leaked FnMut() closure, stored as the closure’s heap address.

The closure is double-boxed (Box<Box<dyn FnMut()>>) and leaked, so its memory outlives any FireHandle copy and can be safely invoked from any context via the raw pointer. The handle is Copy because it only holds the address — repeated invocations on captured copies all resolve to the same underlying closure.

This type replaces the inline Box::leak(... as *mut Box<dyn FnMut()> as usize) pattern that was used by watch!/computed! macros and the virtual list component, encapsulating the unsized coercion, double-boxing, and raw pointer arithmetic behind From/Into conversions and a dedicated fire method.

Implementations

impl FireHandle

Implementation of FireHandle construction, invocation, and conversions.

pub fn new<F>(fire: F) -> Self

where F: FnMut() + 'static,

Leaks the given closure and returns a handle pointing to its heap address.

The closure is double-boxed (Box<Box<dyn FnMut()>>) and leaked so the inner box’s address remains stable for the lifetime of the program. The address is captured as a usize and wrapped in a FireHandle.

Arguments

• F: FnMut() + 'static - The fire closure to leak.

Returns

• FireHandle - A handle holding the leaked closure’s address.

pub unsafe fn fire(self)

Invokes the closure pointed to by this handle.

Takes self by value because FireHandle: Copy — repeated invocations on a single captured handle each copy the address and operate on the same underlying closure.

Safety

The handle must come from FireHandle::new (or From) and the underlying boxed closure must still be live.

pub unsafe fn fire_at(addr: usize)

Invokes the closure stored at the given address.

This is the static counterpart of fire for call sites that have only the raw usize address (e.g., macro-generated code that captures the address by move into a subscribe closure).

Arguments

• usize - The address of a leaked Box<dyn FnMut()>.

Safety

addr must come from a valid FireHandle produced by new (or From) and the underlying boxed closure must still be live.

Trait Implementations

impl Clone for FireHandle

fn clone(&self) -> FireHandle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FireHandle

impl Debug for FireHandle

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

Formats the value using the given formatter.

impl Eq for FireHandle

impl<F> From<F> for FireHandle

where F: FnMut() + 'static,

Leaks a fire closure into a FireHandle.

This is the canonical Into path used by watch!/computed! macros and the virtual list component to obtain a FireHandle from a closure.

fn from(fire: F) -> Self

Leaks this closure and stores its address in the returned handle.

Returns

• FireHandle - A handle holding the leaked closure’s address.

impl From<FireHandle> for usize

Extracts the raw address from a FireHandle.

This is used by macro-generated code that needs to capture the address (a Copy type) into FnMut() + 'static subscribe closures.

fn from(handle: FireHandle) -> Self

Returns the leaked closure’s heap address.

Returns

• usize - The address held by this handle.

impl Hash for FireHandle

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for FireHandle

fn cmp(&self, other: &FireHandle) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for FireHandle

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for FireHandle

fn partial_cmp(&self, other: &FireHandle) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for FireHandle