1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
//! Closure type (equivalent to `&mut dyn FnMut(A) -> R`) that's `repr(C)`.
#[repr(C)]
pub struct Closure<'a, A, R> {
call: unsafe extern "C" fn(&mut Env, A) -> R,
env: &'a mut Env,
}
struct Env;
impl<'a, A, R, F: FnMut(A) -> R> From<&'a mut F> for Closure<'a, A, R> {
fn from(f: &'a mut F) -> Self {
unsafe extern "C" fn call<A, R, F: FnMut(A) -> R>(env: &mut Env, arg: A) -> R {
(*(env as *mut _ as *mut F))(arg)
}
Closure { call: call::<A, R, F>, env: unsafe { &mut *(f as *mut _ as *mut Env) } }
}
}
impl<'a, A, R> Closure<'a, A, R> {
pub fn call(&mut self, arg: A) -> R {
unsafe { (self.call)(self.env, arg) }
}
}
|
