La Vita è Bella

Here's a example to make a virtual class in c++, similar to "interface" in Pascal and Java:

 1 #include <stdio.h>
 2 #include <string>
 3 #include <vector>
 4
 5 class base_foo {
 6 public:
 7         virtual std::string name() { return "base_foo"; }
 8 };
 9
10 class foo: public base_foo {
11 public:
12         std::string name() { return "foo"; }
13 };
14
15 class bar: public base_foo {
16 public:
17         std::string name() { return "bar"; }
18 };
19
20 int main() {
21         std::vector<base_foo*> foo_list;
22         foo f;
23         bar b;
24         foo_list.push_back(&f);
25         foo_list.push_back(&b);
26         printf("%s\n%s\n",
27                         foo_list[0]->name().c_str(),
28                         foo_list[1]->name().c_str());
29         return 0;
30 }

The result of this program is:

foo
bar