prog.cpp: In function ‘int main()’:
prog.cpp:22:10: error: cannot declare variable ‘d’ to be of abstract type ‘Derived’
Derived d;
^
prog.cpp:10:7: note: because the following virtual functions are pure within ‘Derived’:
class Derived
^
prog.cpp:7:16: note: virtual void Base::Foo()
virtual void Foo() = 0;
^