Re: [Boost-users] [bind] How to dereference _1 in a boost::bind expression

Subject: Re: [Boost-users] [bind] How to dereference _1 in a boost::bind expression
From: Sven Gaerner (sgaerner_at_[hidden])
Date: 2008-10-02 06:45:28

On Thu, 2 Oct 2008 11:12:54 +0100
"Peter Barker" <newbarker_at_[hidden]> wrote:

> Hello,
> 
> Here's an example of my problem:
> 
> #include <algorithm>
> #include <vector>
> 
> #include <boost/bind.hpp>
> 
> class TheClass
> {
> };
> 
> void accept(TheClass& tc)
> {
> }
> 
> int main()
> {
> 	std::vector<TheClass*> cont;
> 
> 	// Compile error - how to dereference _1 ???
> 	std::for_each(cont.begin(),cont.end(),boost::bind(&accept,_1));
> }
> 
> How can I dereference _1 so I can use the accept function?
> 
> Regards,
> 
> Pete
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users
> 

You don't have to dereference _1. Your accept function must look like
this:
 void accept(TheClass *arg) {
 }
Your std::vector contains pointers to TheClass so std::for_each()
passes objects of that type to your functor, in this case a
pointer to types of TheClass.

Sven