Code shared from the Rust Playground

playground.rs

use std::sync;
use std::sync::RwLockWriteGuard;
use std::sync::LockResult;

pub struct RwLock<T: ?Sized> {
    pub lock: sync::RwLock<T>,
    //id: &'static str,
}

impl<T> RwLock<T> {
    pub fn new(t: T) -> RwLock<T> {
        RwLock { lock: sync::RwLock::new(t) }
    }
}

impl<T: ?Sized> RwLock<T> {

    #[inline]
    pub fn write(&self) -> LockResult<RwLockWriteGuard<T>> {
        println!("write lock");
        self.lock.write()
    }

}

impl<T: ?Sized> Drop for RwLock<T> {
    
    #[inline]
    fn drop(&mut self) {
        println!("drop write lock");
    }
}


fn main() {
    println!("Hello, world!");

    let lock = RwLock::new(5);
    let mut w = lock.write().unwrap();
    *w += 1;
    assert_eq!(*w, 6);
}