Re: [Boost-users] [multi_index] modify problem with composite_key

From: JOAQUIN LOPEZ MU?Z (joaquin_at_[hidden])
Date: 2007-09-24 17:32:42

Hi Jeffrey

----- Mensaje original -----
De: Jeffrey Holle <jeffreyholle_at_[hidden]>
Fecha: Lunes, Septiembre 24, 2007 11:08 pm
Asunto: [Boost-users] [multi_index] modify problem with composite_key
Para: Boost Users mailing list <boost-users_at_[hidden]>

> I am having problems using the modify method with my composite_key.
> Here is my multi_index container definition:
>   typedef multi_index_container<
>       entry,
>       indexed_by<
>         ordered_unique<member<entry,DataVertex,&entry::m_vertex> >,
>         ordered_non_unique<
>           composite_key<
>             entry,
>             member<entry,int,&entry::m_y>,
>             member<entry,int,&entry::m_x>
>           >
>         >
>       >
>     > C;
> 
> C m_c;
> namespace ll=boost::lambda;
> 
> typedef nth_index<C,1>::type XYINDEX;
> 
> I have a XYINDEX::iterator that is defined using the equal_range 
> method of an XYINDEX order.  Now I wish to modify the m_x
> attribute that this iterator points to so I attempt to write:
> 
> inline void
> Positioner::updateX(XYIterator iter,int x)
> {
>   m_c.modify(iter,(&ll::_1)->*&Positioner::entry::m_x=x);
> }
> 
> I get this compiler error:
[...]

m_c.modify(...) implicitly uses the interface of C's index #0,
yet you're passing it a XYIterator, which belongs to index #1.
Iterators have to be matched with the index they're associated
with:

inline void
Positioner::updateX(XYIterator iter,int x)
{
  // note the get<1>() bit
  m_c.get<1>().modify(
    iter,(&ll::_1)->*&Positioner::entry::m_x=x);
}

Does it work now?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

PS: I posted an answer to some previous question of yours that
you haven't confirmed yet:
http://lists.boost.org/boost-users/2007/09/30804.php
Is it all solved?