Event/ComponentGroup.h

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#ifndef _evt_ComponentGroup_h_
#define _evt_ComponentGroup_h_

#include <utl/ErrorLogger.h>
#include <utl/AugerException.h>

#include <sstream>
#include <utility>

#include <boost/ptr_container/ptr_map.hpp>
#include <boost/iterator/transform_iterator.hpp>


namespace evt  {

  template<class Iterator>
  void
  Check(const Iterator& i, const Iterator& e, const int id)
  {
    if (i == e) {
      std::ostringstream error;
      // XXX See Make.
      error << "Id " << id << " not present.";
      ERROR(error);
      throw utl::NonExistentComponentException(error.str());
    }
  }


  template<class Component>
  class ComponentGroup {
  private:
    /*template< class R >
    struct SecondResolver {
      typedef R result_type;
      template<class Pair>
      R operator()(const Pair& p) const { return *p.second; }
    };*/
    template<class RetType, class ArgType>
    struct SecondResolver {
      typedef RetType result_type;
      typedef ArgType argument_type;
      result_type operator()(const argument_type& p) const { return *p.second; }
    };
    typedef boost::ptr_map<int, Component> InternalComponentCollection;
    // Some More aliases (in const and non-const flavor for some cases)
    typedef typename InternalComponentCollection::key_type KeyType;
    typedef typename InternalComponentCollection::mapped_type MappedType;
    typedef const Component* /* No nested typedef for this...*/ ConstMappedType;
    typedef typename InternalComponentCollection::mapped_reference MappedReference;
    typedef typename InternalComponentCollection::const_mapped_reference ConstMappedReference;
    typedef typename InternalComponentCollection::const_reference ConstReference;
    typedef typename InternalComponentCollection::reference Reference;
    typedef typename InternalComponentCollection::const_iterator PairConstIterator;
    typedef typename InternalComponentCollection::iterator PairIterator;
    // Alternative typedef SecondResolver<ConstMappedReference> ConstComponentResolver;
    // Alternative typedef SecondResolver<MappedReference> ComponentResolver;
    typedef SecondResolver<ConstMappedReference, ConstReference> ConstComponentResolver;
    typedef SecondResolver<MappedReference, Reference> ComponentResolver;
    static constexpr const ConstComponentResolver kConstResolver = ConstComponentResolver();
    static constexpr const ComponentResolver kResolver = ComponentResolver();
  public:
    typedef boost::transform_iterator<ConstComponentResolver, PairConstIterator>
      ComponentConstIterator;
    typedef boost::transform_iterator<ComponentResolver, PairIterator>
      ComponentIterator;
    const Component&
    Get(const int id)
      const
    {
      const PairConstIterator i = fComponents.find(id);
      const PairConstIterator e = fComponents.end();
      Check(i, e, id);
      return *i->second;
    }
    Component&
    Get(const int id)
    {
      const PairIterator i = fComponents.find(id);
      const PairIterator e = fComponents.end();
      Check(i, e, id);
      return *i->second;
    }
    void
    Make(/*const*/ int id)
    {
      // id-constructor
      Component* const c = new Component(id);
      /*
       * The id needs to be non-const due to the needs
       * of the object being called.
       * http://www.boost.org/doc/libs/1_38_0/libs/ptr_container/doc/tutorial.html
       * "Note that must create the key as an lvalue (due to exception-safety issues)..."
       */
      if (!fComponents.insert(id, c).second) {
        /*
         * boost::ptr_map_adapter::insert_impl
         * takes care of destroying if insertion
         * was not performed at last.
         * delete c;
         */
        std::ostringstream error;
        // XXX Put some component label: add a typedef to the Component type?
        error << id << " already present.";
        WARNING(error);
      }
    }
    bool Has(const int id) const { return fComponents.find(id) != fComponents.end(); }

    // XXX Why this isn't unsigned (taken from sdet::SEvent::GetNumberOfStations and others)?
    int GetNumberOf() const { return fComponents.size(); }

    ComponentIterator Begin()
    { return boost::make_transform_iterator(fComponents.begin(), kResolver); }

    ComponentIterator End()
    { return boost::make_transform_iterator(fComponents.end(), kResolver); }

    ComponentConstIterator Begin() const
    { return boost::make_transform_iterator(fComponents.begin(), kConstResolver); }

    ComponentConstIterator End() const
    { return boost::make_transform_iterator(fComponents.end(), kConstResolver); }

  private:
    InternalComponentCollection fComponents;
  };

}


#endif