Why can I write a generic catch statement in C# that does nothing?

Possible Duplicate: Why can’t I catch a generic exception in C#? I have been reviewing and writing Circuit Breaker code recently. The following method compiles, but the catch block is never entered. I have plenty of work-arounds, and this isn't the only way to get the right behavior (filtering exceptions), but I'm curious why this compiles and doesn't work! ``` public void AttemptCall<TException>(Action action) where TException : Exception { try { action(); } catch(TException e) // This block is never entered! { state.ActUponException(e); throw; } } ``` Here is a test that should enter the catch block of the previous method. ``` [TestMethod] public void Throw_an_exception() { circuitBreaker.AttemptCall<Exception>(() => throw new Exception()); // test the circuit breaker's state } ```