Counting matches in vector of structs

Question

I have a problem that requires me to count the number of instances within this array that uses either std::count() or std::find(). I'm aware of how to do this using a standard data (see bottom code) type but not with the NameContainer that I'm using.

//Type
struct NameContainer{
    char name [32];
}

//An array of containers
NameContainer *_storedNames = new NameContainer[_numberOfNames];

//An example of what I'm trying to do with a string rather than the NameContainer
std::vector<string> v(_storedNames, _storedNames + _numberOfNames);
//returns an numeric value
return std::count(v.begin(), v.end(), nameToSearch))

Answer 1

You can use a functor

struct names_equal {
    string comp_to;

    names_equal(string a) : comp_to(a) {}

    bool operator()(NameContainer& p) {
        return p.name == comp_to;
    }
};

And count like

cout << std::count_if(v.begin(), v.end(), names_equal(nameToSearch));

This way nameToSearch doesn't have to be hard coded.

---

EDIT

If you can not use count_if, and has to be count then modify NameContainer and overload == for it.

struct NameContainer{
    string name;

    bool operator==(string str) {
        return name == str;
    }
};

Then count like this

cout << std::count(v.begin(), v.end(), nameToSearch);