Unnamed

class coupled_visitor_2d : public visitor {	public:		coupled_visitor_2d(volume& Volume, long Offset) : visitor(Volume), m_offset(Offset) {}		virtual void visit(particle& Particle, cell& Cell);	private:		class interior_visitor_base : public cell_visitor {			public:			/// MomentumRow and ContinuityRow contain the respective equation numbers.				interior_visitor_base(volume& Volume, particle& Particle, cell& Cell, long MomentumRow, long ContinuityRow, long Offset) : cell_visitor(Volume, Particle, Cell), m_momentum_row(MomentumRow), m_continuity_row(ContinuityRow), m_offset(Offset) {}			protected:				/// Gradient of kernel				vector3 grad(particle& Particle);				/// Calculate momentum coefficients				void momentum(particle& Particle);				/// Calculate continuity coefficients				void continuity(particle& Particle);			private:				long m_momentum_row;				long m_continuity_row;			// only do momentum equations				bool m_momentum_only;			// only do continuity				bool m_continuity_only;				// offset for continuity equation				long m_offset;		}; // class interior_visitor_base		class interior_visitor_momentum : public interior_visitor_base {			public:				interior_visitor_momentum(volume& Volume, particle& Particle, cell& Cell, long MomentumRow, long ContinuityRow, long Offset) : interior_visitor_base(Volume, Particle, Cell, MomentumRow, ContinuityRow, Offset) {}				virtual void visit(particle& Particle, cell& Cell);		};		class interior_visitor_continuity : public interior_visitor_base {			public:				interior_visitor_continuity(volume& Volume, particle& Particle, cell& Cell, long MomentumRow, long ContinuityRow, long Offset) : interior_visitor_base(Volume, Particle, Cell, MomentumRow, ContinuityRow, Offset) {}				virtual void visit(particle& Particle, cell& Cell);		};		class interior_visitor_momentum_continuity : public interior_visitor_base {			public:				interior_visitor_momentum_continuity(volume& Volume, particle& Particle, cell& Cell, long MomentumRow, long ContinuityRow, long Offset) : interior_visitor_base(Volume, Particle, Cell, MomentumRow, ContinuityRow, Offset) {}				virtual void visit(particle& Particle, cell& Cell);		};		long m_offset;}; // class coupled_visitor_2d