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4
<分区>
我正在尝试使用迭代器模式进行迭代和打印，但出现错误
这里是错误:
error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'std::string' (or there is no acceptable conversion)
1> could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>> (std::basic_ostream<_Elem,_Traits> &,const char *)'
这是错误的来源std::cout << menuItem->getName();
#ifndef _ROBOT1_
#define _ROBOT1_
namespace guitars {
namespace Composite {
namespace InventoryParts {
using namespace std;
#include <iostream>
//#include <string>
class Robot1 {
Menu* _partsMenu;
private:
public: Robot1( Menu* parts ) : _partsMenu( parts ) { assert( parts );
}
public: void printMenu() {
Iterator<MenuItem>* partsIterator = _partsMenu->createIterator();
std::cout << "Parts List" << std::endl;
printMenu( partsIterator );
}
private: void printMenu( Iterator<MenuItem>* iterator ) { assert( iterator );
while( iterator->hasNext() ) {
MenuItem* menuItem = dynamic_cast< MenuItem* >( iterator->next() );
std::cout << menuItem->getName();
std::cout << menuItem->getPrice() << " -- ";
std::cout << menuItem->getDescription() << std::endl;
}
}
};
}
}
}
我将包含更多文件以防它在其他地方
#ifndef _ELECTRIC_MENU_ITERATOR_
#define _ELECTRIC_MENU_ITERATOR_
#include "Iterator.h"
namespace guitars {
namespace Composite {
namespace InventoryParts {
class ElectricMenuIterator : public Iterator<MenuItem> {
private: mutable std::vector< MenuItem* > _items;
private: mutable MenuItem* _position;
public: explicit ElectricMenuIterator( std::vector< MenuItem* > items ) :
_items( items ) {
_position = *items.begin();
}
public: MenuItem* next() const {
return _position;
}
public: bool hasNext() const {
for( std::vector< MenuItem* >::iterator iterator = _items.begin(); iterator != _items.end(); iterator++ ) {
if( *iterator == _position ) {
if( ++iterator != _items.end() ) {
_position = *iterator;
return true;
}
else
return false;
}
}
return false;
}
};
}
}
}
#endif
迭代器
#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 {
}
};
}
}
}
#endif
菜单
#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:
public:
virtual Iterator<MenuItem>* createIterator() const = 0;
virtual ~Menu() = 0 {
}
};
}
}
}
和电吉他菜单
#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:
std::vector< MenuItem* > _menuItems;
public: ElectricMenu() {
addItem( "Electric Guitar","comes with an assortment of goodies",542.99);
//addItem( "Regular acoustic","standard style",false,245.99);
}
public: void addItem( std::string name, std::string description, double price ) {
MenuItem* menuItem = new MenuItem( name, description, price );
_menuItems.push_back( menuItem );
}
public: std::vector< MenuItem* > getMenuItems() const {
return _menuItems;
}
public: Iterator<MenuItem>* createIterator() const {
return dynamic_cast<Iterator<MenuItem>* > ( new ElectricMenuIterator( _menuItems) );
}
};
}
}
}
#endif
请原谅我的格式
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4
0
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