GridDefines.h:
typedef TYPELIST_2(Creature, Player) UnitTypes;

DynamicObject.cpp:
DynamicObject::Update {
..
    CellPair p(MaNGOS::ComputeCellPair(m_caster->GetPositionX(), m_caster->GetPositionY()));
    Cell cell = RedZone::GetZone(p);
    cell.data.Part.reserved = ALL_DISTRICT;
    cell.SetNoCreate();

    MaNGOS::DynamicObjectUpdater notifier(*this);
    TypeContainerVisitor<MaNGOS::DynamicObjectUpdater, TypeMapContainer<UnitTypes> > object_notifier(notifier);
    CellLock<GridReadGuard> cell_lock(cell, p);
    cell_lock->Visit(cell_lock, object_notifier, *MapManager::Instance().GetMap(m_caster->GetMapId()));
}

DynamicObject.h

#ifndef MANGOSSERVER_DYNAMICOBJECT_H
#define MANGOSSERVER_DYNAMICOBJECT_H

#include "Object.h"
#include "GridDefines.h"

struct SpellEntry;

class DynamicObject : public Object
{
    public:
        DynamicObject();

        bool Create(uint32 guidlow, Unit *caster, uint32 spellId, uint32 effIndex, float x, float y, float z, int32 duration, float radius);
        void Update(uint32 p_time);
        void Delete();
        bool isFinished() {return deleteThis;}
        uint32 GetSpellId() const { return m_spellId; }
        uint32 GetEffIndex() const { return m_effIndex; }
        uint32 GetDuration() const { return m_aliveDuration; }
        Unit* GetCaster() const { return m_caster; }
        float GetRadius() const { return m_radius; }

    protected:
        Unit* m_caster;
        uint32 m_spellId;
        uint32 m_effIndex;
        int32 m_aliveDuration;
        time_t m_nextThinkTime;
        bool deleteThis;
        float m_radius;
};

namespace MaNGOS
{
    struct MANGOS_DLL_DECL DynamicObjectUpdater
    {
        const DynamicObject &owner;
        DynamicObjectUpdater(const DynamicObject &owner) : owner(owner) {}

        template<class T> inline void Visit(std::map<OBJECT_HANDLE, T *>  &m)
        {
            for(typename std::map<OBJECT_HANDLE, T*>::iterator itr=m.begin(); itr != m.end(); ++itr)
            {
                if(itr->second->isAlive() && !itr->second->isInFlight() )
                {
                    if(owner.GetCaster()->IsFriendlyTo(itr->second) || iter->second->HasAura(owner.GetSpellId(), owner.GetEffIndex()))
                        continue;

                    if(owner.GetDistanceSq(itr->second) < owner.GetRadius() * owner.GetRadius() )
                    {
                        SpellEntry *spellInfo = sSpellStore.LookupEntry(owner.GetSpellId());
                        Aura* Aur = new Aura(spellInfo, owner.GetEffIndex(), itr->second, owner.GetCaster(), NULL);
                        itr->second->AddAura(Aur);
                    }
                }
            }
        }
    };
}

#endif