Cell type whose contents can be accessed only via an inforgeable token.
```rust let mut token = Token::new();
let lock = TokenLock::new(&token, 1); assert_eq!(*lock.read(&token).unwrap(), 1);
let mut guard = lock.write(&mut token).unwrap(); assert_eq!(*guard, 1); *guard = 2; ```
The lifetime of the returned reference is limited by both of the TokenLock
and Token
.
rust
drop(lock); // compile error: cannot outlive `TokenLock`
rust
drop(token); // compile error: cannot outlive `Token`
This also prevents from forming a reference to the contained value when there already is a mutable reference to it:
rust
let write_guard = lock.write(&mut token).unwrap();
let read_guard = lock.read(&token).unwrap(); // compile error
While allowing multiple immutable references:
rust
let read_guard1 = lock.read(&token).unwrap();
let read_guard2 = lock.read(&token).unwrap();
License: MIT/Apache-2.0