Re: [boost] [multi_index] invalid expression as template parameter

From: Joaquín Mª López Muñoz (joaquin_at_[hidden])
Date: 2006-05-22 12:45:11

Tal Agmon ha escrito:

> Please see below code
>

OK, now I can reproduce it. This is indeed MSVC 6.0 bug (one more):
I've tried with GCC and ICC 7.1, and everything goes smooth. Fortunately,
you can always resort to manually writing your key extractors, as described
in http://tinyurl.com/l3g6u; the following workaround with user-defined key
extractors has been checked to work with MSVC 6.5. Hope it helps,

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

******** BEGIN CODE ********
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/mem_fun.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>

typedef int handle;
typedef int group_id;

struct NodeBase:boost::enable_shared_from_this<NodeBase>
{
  virtual ~NodeBase(){}
  virtual group_id memberOf()const=0;
  virtual handle   getHandle()const=0;
};

struct NodeType:NodeBase
{
  NodeType(handle h,group_id gid):h(h),gid(gid){}

  virtual group_id memberOf()const{return gid;}
  virtual handle   getHandle()const{return h;}

private:
  group_id gid;
  handle   h;
};

struct NodeBaseHandleExtractor
{
  typedef handle result_type;
  result_type operator()(const boost::shared_ptr<NodeBase>& x)
  {
    return x->getHandle();
  }
};

struct NodeBaseGroupIdExtractor
{
  typedef group_id result_type;
  result_type operator()(const boost::shared_ptr<NodeBase>& x)
  {
    return x->memberOf();
  }
};

typedef boost::multi_index::multi_index_container<
  boost::shared_ptr<NodeBase>,
  boost::multi_index::indexed_by<
    boost::multi_index::ordered_unique<
      NodeBaseHandleExtractor
    >,
    boost::multi_index::ordered_non_unique<
      NodeBaseGroupIdExtractor
    >
  >
> NodePtrSet;

int main()
{
  NodePtrSet ns;

  typedef boost::shared_ptr<NodeBase> element_type;

  ns.insert(element_type(new NodeType(0,0)));
  ns.insert(element_type(new NodeType(1,0)));
  ns.insert(element_type(new NodeType(2,1)));

  return 0;
}

******** END CODE ********