Public Structure SafeLock 
   Inherits System.ValueType

public struct SafeLock : System.ValueType 

object instance = new object();
using (IDisposable safeLock = new SafeLock(instance, 0))
{
    safeLock.Dispose();//since the using statement has the same boxed pointer to r, we are allowed to dispose
}

Dim instance As New Object()
Using safeLock As IDisposable = New SafeLock(instance, 0)
        'since the using statement has the same boxed pointer to r, we are allowed to dispose
    safeLock.Dispose()
End Using