C++ – map of vectors in STL

cstl

I want to have a map of vectors, (but I don't want to use pointer for the internal vector), is it possible?

// define my map of vector
map<int, vector<MyClass> > map;

// insert an empty vector for key 10. # Compile Error
map.insert(pair<int, vector<MyClass> >(10, vector<MyClass>)); 

I know that if I have used pointer for vector, as follows, it would be fine, but I wonder if I can avoid using pointer and use the above data structure (I don't want to manually delete)

// define my map of vector
map<int, vector<MyClass>* > map;

// insert an empty vector for key 10.
map.insert(pair<int, vector<MyClass>* >(10, new vector<MyClass>)); 

Best Answer

The first data structure will work. You might want to typedef some of the code to make future work easier:

typedef std::vector<MyClass>      MyClassSet;
typedef std::map<int, MyClassSet> MyClassSetMap;

MyClassSetMap map;
map.insert(MyClassSetMap::value_type(10, MyClassSet()));

or (thanks quamrana):

map[10] = MyClassSet();