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use std::any::TypeId;
use std::mem;
use std::mem::MaybeUninit;
use std::pin::Pin;
use std::ptr;
use crate::assert_send;
use crate::spi_async_socket_impl_delegate;
use crate::AsyncSocket;
#[derive(Debug)]
pub struct AsyncSocketBox(Box<dyn AsyncSocket>);
fn _assert_kinds() {
assert_send::<AsyncSocketBox>();
}
fn transmute_or_map<A: 'static, B: 'static>(a: A, f: impl FnOnce(A) -> B) -> B {
if TypeId::of::<A>() == TypeId::of::<B>() {
assert_eq!(mem::size_of::<A>(), mem::size_of::<B>());
unsafe {
let mut b = MaybeUninit::<B>::uninit();
ptr::copy(&a as *const A, b.as_mut_ptr() as *mut A, 1);
mem::forget(a);
b.assume_init()
}
} else {
f(a)
}
}
impl AsyncSocketBox {
pub fn new<S: AsyncSocket>(socket: S) -> AsyncSocketBox {
transmute_or_map(socket, |socket| AsyncSocketBox(Box::new(socket)))
}
fn deref_pin_mut_for_impl_socket(self: Pin<&mut Self>) -> Pin<&mut dyn AsyncSocket> {
Pin::new(&mut self.get_mut().0)
}
fn deref_for_impl_socket(&self) -> &dyn AsyncSocket {
&self.0
}
}
spi_async_socket_impl_delegate!(AsyncSocketBox);
fn _assert_async_socket_box_is_async_socket(s: AsyncSocketBox) {
fn accepts_socket<S: AsyncSocket>(_: S) {}
accepts_socket(s);
}