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)) ); 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

But DiscardableItem::Discard does not be called. How can I make it work?

...

thanks! I think lambda can solve this problem easily.

You don't need boost::lambda here, you can easily solve this with boost::bind

std::for_each( items.rbegin(), items.rend(), boost::bind(&DiscardableItem::Discard, _1) );

If you *want* to use boost::lambda I'm sure someone else will help :)

Regards, Alex

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I think that your advice is a good choice. Using a function object is more clearly. However, if some one know how to do this using Lambda or Bind, please tell me. I want to know it. thanks! 2009/3/23 Christopher Currie

On Sun, Mar 22, 2009 at 8:52 PM, 钱晓明 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)) );

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

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 { void operator()( DiscardableItem * pd ) const { pd->Discard(); delete pd; } };

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

HTH, Christopher _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users