title: How to unlock a rwlock without dropping the lock
body: <p>How to unlock a rwlock? I can't drop the lock since i need it more than 1 time. I have some code like this:</p>
  <pre><code>struct Abc {
      lock: RwLock&lt;()&gt;,
      data: usize,
  }
  
  let a = Abc {
      RwLock::new(()),
      data: 0,
  };
  
  a.lock.read().unwrap();
  // do something with data
  // now i need to unlock a.lock so others threads can use it
  
  </code></pre>