cpp make class abstract

1struct Abstract
2{
3     virtual ~Abstract() = 0;
4};
5
6Abstract::~Abstract() {}
7
8struct Valid: public Abstract
9{
10        // Notice you don't need to actually overide the base
11        // classes pure virtual method as it has a default
12};
13
14
15int main()
16{
17    // Abstract        a;  // This line fails to compile as Abstract is abstract
18    Valid           v;  // This compiles fine.
19}