Events in D

[bitwise via Digitalmars-d]

On Tuesday, 29 August 2017 at 05:10:25 UTC, bitwise wrote:
> [...]

I think I should clarify for anyone with limited C# experience, 
that I'm talking about the custom-event syntax, not the regular 
one-liner syntax:

class MyClass
{
     Object myLock;
     EventHandler _completed;

     public event EventHandler Completed
     {
         add {
             lock (myLock) {
                 _completed = 
(EventHandler)Delegate.Combine(_completed, value);
                 // update some other state
             }
         }
         remove {
             lock(myLock) {
                 _completed = 
(EventHandler)Delegate.Remove(_completed, value);
                 // update some other state
             }
         }
     }

     void RaiseCompleted()
     {
         EventHandler c = null;

         lock(myLock) {
             c = _completed;
         }

         if(c != null)
             c();
     }
}