I'm looking for advice on using std::max_element() with boost::multi_array. When passing a multi_array to max_element() I was expecting to get an iterator referring to the largest element in return. However my compiler tells me the iterator refers to a sub_array<class RAClass::RAPoint,1> instead, and I don't know why or what to do about it. Its clear that inexperience with multi_array and max_element() is the cause. Is anyone able to shed some light on the subject? Details: ―--- .h file ―--- namespace RAClass { typedef boost::multi_array<RAPoint,2> CELL_TABLE; CELL_TABLE* m_cells; ―--- .cpp file ―--- CELL_TABLE::iterator e = std::max_element(m_cells->begin(),m_cells->end(), RAPoint::lower); // RAPoint::lower() compares two RAPoints int height = e->getHeight(); ―--- compiler output ―--- getHeight' : is not a member of 'sub_array<class RAClass::RAPoint,1>' TIA Neil (J Mackie). By the end of this year the Radiocommunications Agency and all responsibility for regulating the radio spectrum and communications services will become part of Ofcom - the new converged regulator for the communications sector. See the Ofcom transitional website at www.Ofcom.org.uk for more details.