Blog - virtual base classes in c++

ive written short piece of code... but it didnt worked. i must write this code down somewhere. im almost sure that next time i will have to deal with virtual inheritance in c++ i will make this mistake once again. lets take a look at this few lines of code :

class A { ... }
class B : public virtual A 
{ 
 B( void ) : A( void ){ ... }
}
class C : public B 
{
 C( void ) : B(void ){ ... }
}

what is wrong ? ive asked myself
well... C class constructor should also invoke direct call to class A constructor. bleh... thats easy, isnt that... not for me hehe