On Thu, May 15, 2008 at 3:06 AM, Daniel Walker <daniel.j.walker@gmail.com> wrote:
I've attached a file that provides a simple unary implementation of all this as a proof of concept and to give an idea of what the boilerplate would look like. It should work for both C++03 and 0x. I tested with gcc 4.3. If there's interest, maybe this and Marco's work and possible parts of Egg could be organized into something really useful.
Hi Daniel, thanks a lot definitely there is interest, I will take a deep look at Egg (that I don't know) and also to your polymorphic_function<> On this I have a naive question, just to clear the things for me. The point of Giovanni is to use a generalized callback for type erasure of underlying function, but when you write function<int(int,int)> f0 = functional_cast<plus(int,int)>(add_floats); function<float(float,float)> f1 = functional_cast<plus(float,float)>(add_ints); The fact that the poly class is "plus" it's explicit anyway. IOW what's the difference of the above from function<int(int,int)> f0 = plus(); function<float(float,float)> f1 = plus(); Again, in other words, does functional cast support this ? struct g { template <class> struct result; template <class T> struct result<g(T)> { typedef T type; }; template<class T> T operator()(T t) { return t; } int internal_state; g() : internal_state(0) {} }; function<float(float,float)> add_floats = plus(); add_floats.internal_state = 7; function<int(int,int)> add_ints = plus(); std::cout << add_ints.internal_state; // it's 0 of course function<int(int,int)> f0 = functional_cast<plus(int,int)>(add_floats); std::cout << f0.internal_state; // if it's 7 then you have made something very very interesting Thanks Marco