use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
/// Internal helper struct to assert that a future is send.
#[pin_project::pin_project]
pub(crate) struct AssertSend<T>(#[pin] T);
impl<T> AssertSend<T> {
/// Assert that the given inner value is `Send` by some external invariant.
///
/// # Safety
///
/// ProtocolCaller must assert that nothing is done with inner that violates it
/// being `Send` at runtime.
pub(crate) unsafe fn new(inner: T) -> Self {
Self(inner)
}
}
// Safety: we wrap all APIs around the [VmExecution], preventing values from
// escaping from contained virtual machine.
unsafe impl<T> Send for AssertSend<T> {}
impl<T> Future for AssertSend<T>
where
T: Future,
{
type Output = T::Output;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
this.0.poll(cx)
}
}