pub(crate) type Result<T> = Result<T, Box<dyn Any + Send>>;
Expand description
A specialized Result
type for threads.
Indicates the manner in which a thread exited.
The value contained in the Result::Err
variant
is the value the thread panicked with;
that is, the argument the panic!
macro was called with.
Unlike with normal errors, this value doesn’t implement
the Error
trait.
Thus, a sensible way to handle a thread panic is to either:
- propagate the panic with
std::panic::resume_unwind
- or in case the thread is intended to be a subsystem boundary
that is supposed to isolate system-level failures,
match on the
Err
variant and handle the panic in an appropriate way
A thread that completes without panicking is considered to exit successfully.
§Examples
Matching on the result of a joined thread:
use std::{fs, thread, panic};
fn copy_in_thread() -> thread::Result<()> {
thread::spawn(|| {
fs::copy("foo.txt", "bar.txt").unwrap();
}).join()
}
fn main() {
match copy_in_thread() {
Ok(_) => println!("copy succeeded"),
Err(e) => panic::resume_unwind(e),
}
}
Aliased Type§
enum Result<T> {
Ok(T),
Err(Box<dyn Any + Send>),
}