Hi,
The following program uses virtual functions. Essentially I need to go
through all the pairs in 'v'.
Since I have already know what are in v at compile time. I would like
to convert the dynamic polymorphism to template. Therefore, the
runtime would be better. I think this should be done with the help of
boost::mpl. But I'm not sure how to do it. Would you please help me?
Thanks,
Peng
#include <iostream>
#include <vector>
#include
struct shape {
virtual void show_me() const = 0;
virtual ~shape() { }
};
struct square : public shape {
void show_me() const {
std::cout << "square";
}
};
struct circle : public shape {
void show_me() const {
std::cout << "circle";
}
};
struct triangle : public shape {
void show_me() const {
std::cout << "triangle";
}
};
int main() {
std::vector v;
{
boost::shared_ptr<shape> s(new square);
v.push_back(s);
}
{
boost::shared_ptr<shape> s(new circle);
v.push_back(s);
}
{
boost::shared_ptr<shape> s(new square);
v.push_back(s);
}
{
boost::shared_ptr<shape> s(new triangle);
v.push_back(s);
}
for(std::vector::const_iterator it =
v.begin(); it != v.end(); ++ it) {
for(std::vector::const_iterator it2 =
it + 1; it2 != v.end(); ++ it2) {
(*it)->show_me();
std::cout << " vs. ";
(*it2)->show_me();
std::cout << std::endl;
}
}
}
