Re: [Boost-users] [lambda]How can I call function of objects in std::list while using std::for_each?

Subject: Re: [Boost-users] [lambda]How can I call function of objects in std::list while using std::for_each?
From: Christopher Currie (christopher_at_[hidden])
Date: 2009-03-23 02:34:13

On Sun, Mar 22, 2009 at 8:52 PM, 钱晓明 <kyleqian_at_[hidden]> wrote:
> I am sorry that I did not figure out the whole intention. Beside calling
> member function, I hope to delete the object immediately.
> I wrote the code at first time:
>
> std::for_each( items.rbegin(), items.rend(),
> (_1->*&DiscardableItem::Discard, bind(delete_ptr(), _1))Â );
>
> after for_each, objects deleted, but Discard function did not been called.
> If using Bind can do the same thing, please tell me. thanks!
> 2009/3/23 Alex MDC <alex.mdc_at_[hidden]>

At this point, though you probably *can* do what you want with bind,
you may want to consider if it will be easier (and clearer in intent)
to simple write a function object that implements your desired
behavior:

struct Discarder : std::unary_function<DiscardableItem*,void>
{
  void operator()( DiscardableItem * pd ) const
  {
    pd->Discard();
    delete pd;
  }
};

std::for_each( items.rbegin(), items.rend(), Discarder() );

HTH,
Christopher