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#![allow(missing_docs)]
use alloc::boxed::Box;
use core::kinds::Send;
use core::ops::FnOnce;
pub struct Thunk<A=(),R=()> {
invoke: Box<Invoke<A,R>+Send>
}
impl<R> Thunk<(),R> {
pub fn new<F>(func: F) -> Thunk<(),R>
where F : FnOnce() -> R, F : Send
{
Thunk::with_arg(move|: ()| func())
}
}
impl<A,R> Thunk<A,R> {
pub fn with_arg<F>(func: F) -> Thunk<A,R>
where F : FnOnce(A) -> R, F : Send
{
Thunk {
invoke: box func
}
}
pub fn invoke(self, arg: A) -> R {
self.invoke.invoke(arg)
}
}
pub trait Invoke<A=(),R=()> {
fn invoke(self: Box<Self>, arg: A) -> R;
}
impl<A,R,F> Invoke<A,R> for F
where F : FnOnce(A) -> R
{
fn invoke(self: Box<F>, arg: A) -> R {
let f = *self;
f(arg)
}
}