Strange Behevior when trying to create a Template containing maps

[danalovesc]

Hi all, i'm new to Templates and when i tried to implement templates methods which needs to use a map (which is a member in private), the map can only do 3 things: insert, swap, and operator =. and i don't get the full functionality of map..

Here's the code:

#ifndef __GARAGE_H_
#define __GARAGE_H_
#include <map>
using namespace std;
template <class T,class SortKey, class SearchKey>
class GarageDataBase
{
public :

	GarageDataBase();
	virtual ~GarageDataBase();	
    const T& Top() const;
	bool Add(T data,SortKey key2, SearchKey key2);
	T Remove(SearchKey toRemove);
	T Find(SearchKey toFind) const;
	bool isEmpty()const;
	


private:
	multimap<SortKey,T> firstMap;
	multimap<SearchKey,pair<SortKey,T>*> secondMap;

};
#endif



template <class T,class SortKey, class SearchKey> GarageDataBase<T,SortKey,SearchKey>::GarageDataBase()
{

}

template <class T,class SortKey, class SearchKey> GarageDataBase<T,SortKey,SearchKey>::~GarageDataBase()
{
}

template <class T,class SortKey, class SearchKey> const T& GarageDataBase<T,SortKey,SearchKey>::Top() const
{
	firstMap.
}

in the last func when trying to get into firstMap mathods, all i get is: insert, swap or, =...


how do i get to "first" or s"econd" in the map?


Thank you and sorry i'm just a beginner here

[weaknessforcats]

firstMap.first and firstMap.second .

Remember, map<> entries are pair<> objects.

first and second are public data members of the pair<> used in the map<> entry.

[weaknessforcats]

Let me try this again. Please ignore my previous post.

multimap<SortKey,int> firstMap; 
  pair<SortKey, int> var;
  SortKey key;
  multimap<SortKey, int>::iterator itr;
 itr = firstMap.find(key);
 itr->first;
  //OR
 (*itr).first;

maps are trees with pair entries. The pair has two public members first and second.

So in the code above, you have a map. Then there is a pair<SortKey, int> object named var. var can be inserted in the map.

To find a pair object inside a map you can use the map's find method. This method returns an iterator to the pair that was located in the map. An iterator is a pointer to that pair.

So an iterator itr was created.

Then you find the pair<> using the map's find method. It returns an iterator to a pair<SortKey, int>. Using that iterator, you access the pair's first and second members.

If the iterator is equal to firstMap.end(), then yur key was not located in the map.