gistfile1.cpp

#ifndef FUNCTION_H_
# define FUNCTION_H_

#include <cstdlib>

template<class T>
class Function
{
public:
    Function() : _obj(NULL), _func(NULL) {}
    virtual ~Function() { delete _inner; }
    template<class U>
    Function(U* obj) : _obj(NULL), _func(NULL) { _obj = new InnerClass<U>(obj); }
    Function(T* func) : _obj(NULL), _func(func) {}

    template<class U>
    void operator=(U* obj) { delete _obj; _obj = new InnerClass<U>(obj); _func = NULL; }

private:
    template<class U>
    class InnerClass
    {
    public:
        InnerClass() : _obj(NULL) {}
        InnerClass(U* obj) : _obj(obj) {}
    private:
        U* _obj;
    };

    InnerClass* _inner;
    T* _func;
};

template<class Retour>
class Function<Retour(void)>
{
public:
    Function(Retour(*func)(void)) : _obj(NULL), _func(func) {}

    void operator=(Retour(*func)(void)) { _func = func; if (_inner) { delete _inner; _inner = NULL; } }

    Retour operator()() { return _inner ? inner->operator()() : _func(); }

private:
    template<class U>
    class InnerClass
    {
    public:
        Retour operator()(void) { return _obj(); }
    };

    Retour(*_func)(void);
};

template<class Retour, class T>
class Function<Retour(T)>
{
public:
    Function(Retour(*func)(void)) : _obj(NULL), _func(func) {}

    void operator=(Retour(*func)(T)) { _func = func; if (_inner) { delete _inner; _inner = NULL; } }

    Retour operator()(T t) { return _inner ? inner->operator()(t) : _func(t); }

private:
    template<class U>
    class InnerClass
    {
    public:
        Retour operator()(T t) { return _obj(t); }
    };

    Retour(*_func)(T);
};

template<class Retour, class T, class I>
class Function<Retour(T, I)>
{
public:
    Function(Retour(*func)(void)) : _obj(NULL), _func(func) {}

    void operator=(Retour(*func)(T, I)) { _func = func; if (_inner) { delete _inner; _inner = NULL; } }

    Retour operator()(T t, I i) { return _inner ? inner->operator()(t, i) : _func(t, i); }

private:
    template<class U>
    class InnerClass
    {
    public:
        Retour operator()(T t, I i) { return _obj(t, i); }
    };

    Retour(*_func)(T, I);
};

template<class Retour, class T, class I, class K>
class Function<Retour(T, I, K)>
{
public:
    Function(Retour(*func)(void)) : _obj(NULL), _func(func) {}

    void operator=(Retour(*func)(T, I, K)) { _func = func; if (_inner) { delete _inner; _inner = NULL; } }

    Retour operator()(T t, I i, K k) { return _inner ? inner->operator()(t, i, k) : _func(t, i, k); }

private:
    template<class U>
    class InnerClass
    {
    public:
        Retour operator()(T t, I i, K k) { return _obj(t, i, k); }
    };

    Retour(*_func)(T, I, K);
};

template<class Retour, class T, class I, class K, class L>
class Function<Retour(T, I, K, L)>
{
public:
    Function(Retour(*func)(void)) : _obj(NULL), _func(func) {}

    void operator=(Retour(*func)(T, I, K, L)) { _func = func; if (_inner) { delete _inner; _inner = NULL; } }

    Retour operator()(T t, I i, K k, L l) { return _inner ? inner->operator()(t, i, k, l) : _func(t, i, k, l); }

private:
    template<class U>
    class InnerClass
    {
    public:
        Retour operator()(T t, I i, K k, L l) { return _obj(t, i, k, l); }
    };

    Retour(*_func)(T, I, K, L);
};



#endif /* !FUNCTION_H_ */