Re: [Boost-users] [Fusion] fusion::for_each with stateful functors

Zitat von Paul Graphov :

Hello Boost Users,

More than three years ago this question arose in this list:

http://lists.boost.org/boost-users/2007/03/26338.php

And as I understand it was concluded that overload for non-const references should be added. But now there are only const references to functor available. Was it forgotten or there are some reasons not to have such overload?

What is the best way to solve the problem? Mutable members or some proxies look quirky.

without reading the thread, I doubt there is a consensus that algorithm functors should be mutable. you can create a functor that refers to mutable state, e.g. using Boost.Bind: void f(int &state,T &e); int main(){ int state=0; fusion::for_each(vec,bind(&f,ref(state),_1)); }