template <class TypeSolver,  class TypeSolverVector,
          class TypeContext, typename TN>
class BOPTools_ContextFunctor
{
  typedef NCollection_DataMap<Standard_ThreadId, TypeContext, Hasher> ContextMap;

public:

  //! Constructor
  explicit BOPTools_ContextFunctor( TypeSolverVector& theVector )
  : mySolverVector(theVector) {}

  //! Binds main thread context
  void SetContext( TypeContext& theContext )
  {
    myContexts.Bind(OSD_Thread::Current(), theContext);
  }

  //! Returns current thread context
  TypeContext& GetThreadContext() const
  {
    const Standard_ThreadId aThreadID = OSD_Thread::Current();
    if ( myContexts.IsBound(aThreadID) )
    {
      TypeContext& aContext = myContexts(aThreadID);
      if ( aContext.IsNull() == Standard_False )
        return aContext;
    }

    // Create new context
    TypeContext aContext = new TN
      ( NCollection_BaseAllocator::CommonBaseAllocator() );

    Standard_Mutex::Sentry aLocker(myMutex);
    myContexts.Bind(aThreadID, aContext);

    return myContexts(aThreadID);
  }

  //! Defines functor interface
  void operator()( const Standard_Integer theIndex ) const
  {
    TypeContext& aContext = GetThreadContext();
    TypeSolver&  aSolver  = mySolverVector(theIndex);

    aSolver.SetContext(aContext);
    aSolver.Perform();
  }

private:
  TypeSolverVector&      mySolverVector;
  mutable ContextMap     myContexts;
  mutable Standard_Mutex myMutex;
};

  void operator() (int theThreadIndex,
                   int theElemIndex) const