Struct r3_core::closure::Closure

pub struct Closure { /* private fields */ }

A light-weight closure, which is comprised of a function pointer and an environment parameter.

Implementations

impl Closure

pub const unsafe fn from_raw_parts(
    func: unsafe extern "C" fn(_: ClosureEnv),
    env: ClosureEnv
) -> Self

Construct a Self from a function pointer and an associated pointer parameter.

Safety

Safe code that has access to the constructed Self will be able to execute func(env, _). A corollary is that, if func has additional safety requirements that are not covered by Closure, they are lost by this function, which means the resulting Closure mustn’t be exposed to safe code.

pub const fn from_fn_const<T: FnOnce() + Copy + Send + 'static>(func: T) -> Self

Construct a Self from the given closure at compile time.

The conversion may involve compile-time heap allocation (core::intrinsics::const_allocate). It’s illegal to call this function at runtime.

Examples

use r3_core::closure::Closure;

// Zero-sized
const C1: Closure = Closure::from_fn_const(|| {});

// CTFE-heap-allocated
const C2: Closure = {
    let x = 42;
    Closure::from_fn_const(move || assert_eq!(x, 42))
};

C1.call();
C2.call();

Don’t call it at runtime:

use r3_core::closure::Closure;
let x = [1, 2, 3];
Closure::from_fn_const(move || { let _x = x; });

pub fn call(self)

Call the closure.

pub const fn func(self) -> unsafe extern "C" fn(_: ClosureEnv)

Get the function pointer.

pub const fn env(self) -> ClosureEnv

Get the pojnter parameter.

pub const fn as_raw_parts(
    self
) -> (unsafe extern "C" fn(_: ClosureEnv), ClosureEnv)

Decompose self into raw components.

Trait Implementations

impl Clone for Closure

fn clone(&self) -> Closure

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Closure

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

Formats the value using the given formatter.

impl Default for Closure

fn default() -> Self

Returns the “default value” for a type.

impl Init for Closure

const INIT: Closure = _

The default value.

impl IntoClosureConst for Closure

const fn into_closure_const(self) -> Closure

Perform conversion to Closure, potentially using a compile-time heap.

impl Copy for Closure