c++ - no appropriate default constructor available - iterator? -

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i cant code compile. added in iterator design pattern , think cause of error: when click on error takes me class electricmenu constructor.. maybe virtual iterator in menu class causing it?

error c2512: 'guitars::composite::inventoryparts::menu' : no appropriate default constructor available

i have composite design pattern , tring incorporate iterator design pattern , maybe cause since maybe have wrong interface.

here code error originating. not doing in main yet, wont compile. include 1 class if thought culprit. trying keep short possible..sorry dont lose interest please

#ifndef _electric_menu_ #define _electric_menu_ #include "menu.h" #include "menuitem.h" #include "electricmenuiterator.h"  namespace guitars { namespace composite { namespace inventoryparts {  class electricmenu : public menu { private:        static const int max_items = 6;      int _numberofitems;      menuitem** _menuitems;    public:       electricmenu() : _numberofitems( 0 )           // error takes me         {                                    _menuitems = new menuitem*[max_items + 1];  // added 1 additional entry;     for( int = 0; <= max_items; i++ ) {     // hold null ( 0 ) value         _menuitems[i] = 0;                      // hasnext() work     }      additem( "electric","flying v", true, 2.99);  }   void additem( std::string name, std::string description, bool vegetarian, double price) {     menuitem* menuitem = new menuitem(name, description, vegetarian, price);     if( _numberofitems >= max_items) {         std::cerr << "sorry, menu full!  can't add item menu" << std::endl;     } else {         _menuitems[_numberofitems] = menuitem;         _numberofitems++;     } } menuitem** getmenuitems() const {     return _menuitems; } iterator<menuitem>* createiterator() const {     return dynamic_cast< iterator< menuitem >* >( new electricmenuiterator( _menuitems) ); }   };  }  }  }   #endif

iterator

#ifndef _electric_menu_iterator_ #define _electric_menu_iterator_ #include "iterator.h"  namespace guitars { namespace composite { namespace inventoryparts {   class electricmenuiterator : public iterator<menuitem> { private:       menuitem** _items;     mutable int _position;    public:      explicit electricmenuiterator(menuitem** items) :     _items(items), _position( 0 ) { }      menuitem* next() const {     menuitem* menuitem = _items[_position];     _position++;     return menuitem; }      bool hasnext() const {     if( _items[_position] == 0 ) {         return false;     } else {         return true;     } }     void remove() { } };  }  }  }   #endif

iterator

#ifndef _iterator_ #define _iterator_  namespace guitars { namespace composite { namespace inventoryparts {  template <class t> class iterator {  public:  virtual bool hasnext() const = 0; virtual t* next() const = 0; virtual ~iterator() = 0 { }   };

heres menu...

#ifndef _menu_ #define _menu_  #include "menucomponent.h" #include "inventoryitem.h" #include "iterator.h" #include <assert.h> #include <vector> #include "menuitem.h"   namespace guitars { namespace composite { namespace inventoryparts {   class menu : public menucomponent {  private:      std::string _name;     std::string _description;     mutable std::vector< menucomponent* > _menucomponents;  public:        virtual iterator<menuitem>* createiterator() const = 0;      virtual ~menu() = 0 { }     menu( const std::string name, const std::string description ) :     _name( name ), _description( description ) { } void add( menucomponent* menucomponent ) { assert( menucomponent );     _menucomponents.push_back( menucomponent ); } void remove( menucomponent* menucomponent ) { assert( menucomponent );     //std::remove( _menucomponents.begin(), _menucomponents.end(), menucomponent ); } menucomponent* getchild( int ) const {     return _menucomponents[i]; } std::string getname() const {     return _name; } std::string getdescription() const {     return _description; } void print() const {     std::cout << std::endl << getname().c_str();     std::cout << ", " << getdescription().c_str() << std::endl;     std::cout << "---------------------" << std::endl;      std::vector< menucomponent* >::iterator iterator = _menucomponents.begin();     while( iterator != _menucomponents.end() ) {         menucomponent* menucomponent = *iterator++;         menucomponent->print();     } } };  }  }  }

thank taking time me.. sorry if long.

your menu class doesn't have default constructor. 2 constructors implicitly declared copy constructor , user-declared constructor:

menu( const std::string name, const std::string description )

because of this, must explicitly initialize menu base class subobject in initialization list of electricmenu constructor.

electricmenu() : menu("name", "description"), _numberofitems( 0 )

alternatively, can declare default constructor menu class; whether makes sense depends on how expect menu used.


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