syn/
thread.rs

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1use std::fmt::{self, Debug};
2use std::thread::{self, ThreadId};
3
4/// ThreadBound is a Sync-maker and Send-maker that allows accessing a value
5/// of type T only from the original thread on which the ThreadBound was
6/// constructed.
7pub struct ThreadBound<T> {
8    value: T,
9    thread_id: ThreadId,
10}
11
12unsafe impl<T> Sync for ThreadBound<T> {}
13
14// Send bound requires Copy, as otherwise Drop could run in the wrong place.
15unsafe impl<T: Copy> Send for ThreadBound<T> {}
16
17impl<T> ThreadBound<T> {
18    pub fn new(value: T) -> Self {
19        ThreadBound {
20            value,
21            thread_id: thread::current().id(),
22        }
23    }
24
25    pub fn get(&self) -> Option<&T> {
26        if thread::current().id() == self.thread_id {
27            Some(&self.value)
28        } else {
29            None
30        }
31    }
32}
33
34impl<T: Debug> Debug for ThreadBound<T> {
35    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
36        match self.get() {
37            Some(value) => Debug::fmt(value, formatter),
38            None => formatter.write_str("unknown"),
39        }
40    }
41}
syn/thread.rs

syn/
thread.rs
