Re: [Boost-users] boost::bind to member variables

From: Stuart Dootson (stuart.dootson_at_[hidden])
Date: 2006-03-29 18:06:47

On 3/29/06, Nico Galoppo <nico_at_[hidden]> wrote:
> Hi,
>
> what kind of object does boost::bind return when binding to a class member
> variable ?  (as opposed to a member method). Is it a function object too?
>
> More in particular, I would like to write a generic free function that applies
> an operation on a particular member variable, passed in with boost::bind.
> Something like this:
>
> struct A {
>   int value;
> };
>
> void f(bind_return_type& membervar)
> {
>    membervar = 3;
> }
>
> A a;
> f(bind(&A::value, a));
>
>
> Thanks.
>
> --nico
>

Couldn't you just do

void f(int& membervar)
{
  membervar = 3;
}

A a;
f(a.value);

?
To get back to bind return types - they're not simple. Your best bet
is to use boost::function to hold the result of boost::bind if you
want to keep it around. Just make sure any variables involved are
still alive when the function is eventually invoked.

Stuart Dootson