functional-inheritance.cpp

// Simple test for using std::function with inheritance
#include <functional>
#include <iostream>

class Base
{
public:
    virtual void do_it(const std::string & s)
    {
        std::cout << "Doing " << s << std::endl;
    }
};

class Derived : public Base
{
public:
    void do_it(const std::string & s) override
    {
        for (int i = 0; i < 5; ++i)
        {
            std::cout << i << ": ";
            Base::do_it(s);
        }
    }
};

typedef std::function<void(const std::string &)> mfunc;

int main()
{
    using namespace std::placeholders;

    Base b;
    Derived d;

    mfunc f1 = std::bind(&Base::do_it, b, _1);
    mfunc f2 = std::bind(&Base::do_it, d, _1);

    f1("important work...");
    f2("important work 5 times");

    auto f3 = std::bind(&Base::do_it, b, _1);

    f3("a bit of time off...");
}