Question

Code written in C++

Environment: Microsoft Visual Studio

I have a vector of maps.
First I want to iterate through the first map, get its ‘first’ and ‘second’ and save them in some other structure I built (a map of vectors).
And then I’ll iterate through the left maps in my “vector of maps” and do the same…

Here’s my vector of maps:

typedef vector<map<string,unsigned int>> myvec;

And here’s the function that should do the work:

void Coogle::make_index(const myvec& the_vec)
{
    //SCAN THE FIRST MAP
    map<string,unsigned int>::iterator map_iter;
    index::iterator idx_iter = the_index.begin();
    for(map_iter=the_vec[0].begin(); map_iter!=the_vec[0].end(); ++map_iter)
    {

    }
}

The ‘for’ loop should iterate through the first map in the vector.
I declared a map iterator because I need it to iterate though the map! Right?
Why isn’t it working?

the error:

IntelliSense: no operator “=” matches these operands

Thanks a lot !!!

---

OK now I identified this iterator:

index::iterator idx_iter = the_index.begin();

And here’s my ‘index’:

typedef map<string,vector<unsigned int>> index;

And inside the mentioned ‘for’ loop I did the following:

    for(map_iter=the_vec[0].begin(); map_iter!=the_vec[0].end(); ++map_iter)
    {
        /*#1*/ idx_iter->first = map_iter->first;
        /*#2*/ idx_iter->second[0] = map_iter->second;
        /*#3*/ idx_iter++;
    }

#2 seems to be ok. But #1 generates an error:

IntelliSense: no operator “=” matches these operands

It’s the same error like the one before so I’m guessing it’s a similar problem.
Is it?

edit: To be more clear, what I wanna do is add from const myvec& the_vec to the ‘i’ location (in this case ‘0’) to my index.

Again :

typedef vector<map<string,unsigned int>> myvec;
typedef map<string,vector<unsigned int>> index;

Thank you!

Answer 1

the_vec is passed as reference to constant, so you need const_iterator:

map<string,unsigned int>::const_iterator map_iter;