I'm trying to store a calbacl in a struct:
struct OpenVPNSocket {
socket_send_callback: Option<Box<dyn FnMut(Vec<u8>) -> Result<(), ()>>>,
}
impl OpenVPNSocket {
fn set_socket_send<F: FnMut(Vec<u8>) -> Result<(), ()>>(&mut self, callback: Box<F>) {
self.socket_send_callback = Some(callback);
}
}
I get this error:
error[E0310]: the parameter type `F` may not live long enough
--> src/lib.rs:8:42
|
7 | fn set_socket_send<F: FnMut(Vec<u8>) -> Result<(), ()>>(&mut self, callback: Box<F>) {
| -- help: consider adding an explicit lifetime bound...: `F: 'static +`
8 | self.socket_send_callback = Some(callback);
| ^^^^^^^^ ...so that the type `F` will meet its required lifetime bounds
I understand lifetime as something to do with references. However I don't use references. I don't see why my struct cannot store a Box
. A Box
lives as long as it's used.