CODE:

#include
#include
#include
#include

template
class if_functor{
	CondT cond;
	FunctorT functor;
public:
	if_functor(CondT cond_,FunctorT functor_):cond(cond_),functor(functor_),else_(*this){}
	template
	void operator ()(const T& value)const{
		if(cond(value)){
			functor(value);
		}
	}
	template
	class else_functor{
		CondT cond;
		FunctorT functor;
		FunctorT2 functor2;
	public:
		else_functor(CondT cond_,FunctorT functor_,FunctorT2 functor2_):cond(cond_),functor(functor_),functor2(functor2_){}
		template
		void operator()(const T& value){
			cond(value) ? functor(value) : functor2(value) ;
		}
	};
	class else_functor_factory{
		const if_functor&parent;
	public:
		else_functor_factory(const if_functor&parent_):parent(parent_){}
		template
		else_functor operator[](FunctorT2 functor){
			return else_functor(parent.cond,parent.functor,functor);
		}
	}else_;
};

template
class if_functor_factory;

template
if_functor_factory if_(CondT cond){
	return if_functor_factory(cond);
}

template
class if_functor_factory{
	CondT cond;
public:
	template
	if_functor operator[](FunctorT functor){
		return if_functor(cond,functor);
	}
	friend if_functor_factory if_(CondT cond);
private:
	if_functor_factory(CondT &cond_):cond(cond_){}
};

struct is_longer_than_7{
	bool operator()(const std::string& value){
		return value.length() > 7;
	}
};

struct when_longer_than_7{
	void operator()(const std::string& value){
		std::coutarray;
	array.push_back("a");
	array.push_back("abc");
	array.push_back("abcde");
	array.push_back("abcdefg");
	array.push_back("abcdefgh");
	array.push_back("abcdefghij");
	std::for_each(array.begin(),array.end(),
		if_(is_longer_than_7())[
			when_longer_than_7()
		].else_[
			when_shorter_than_8()
		]
	);
}