Function adapters, currying: how to build a generalized binder?

[Giovanni Gherdovich]

Hello,

as you know the algorithm std::accumulate in the
version

template<class In, class T, class BinOp>
T accumulate(In first, In last, T init, BinOp op)
{
while(first != last) init = op(init,*first++);
return init;
}

(from the header <numeric>) requires a binary function
as third argument.

Well, consider if I have a function object like this

struct some_operation
{
double operator()(double x, double y, double z)
{
return sin( pow(x*y,2) * z); // or any operation you like
}
}

I would like to bind, say, the first argument x to
a fixed value, then make a binary function out of my
ternary function some_operation, and provide it to
the algorithm std::accumulate.

Is there any standard way to do such binding?
I know the function adapters std::bind1st and std::bind2nd,
but thay work only for binary functions and yeld unary
functions...
Is there any way to use these two binders to build
more general binders?

Best regards,
Giovanni Gh.

 

[gpderetta]

[...]
Is there any standard way to do such binding?

Check boost.bind, which will also be in the next standard.

I know the function adapters std::bind1st and std::bind2nd,
but thay work only for binary functions and yeld unary
functions...
Is there any way to use these two binders to build
more general binders?

I do not think so, and anyways, any solution involving the (current)
standard binders will easily drive you insane

 

[Giovanni Gherdovich]

Hello!

gpd:

Check boost.bind, which will also be in the next standard.

Cool!
boost.bind does _exactly_ what I wish!
http://www.boost.org/doc/libs/1_36_0/libs/bind/bind.html

Dear boost project, from now on you have one more fan

Giovanni Gh.