Weighted random function

random.cpp

#include <iostream>
#include <array>
#include <map>
#include <random>

using std::cout;
using std::endl;
using std::string;
using std::array;

class item
{
public:
    string name;
    int weight;
};

struct descending
{
    template <class item>
    bool operator()(item const &a, item const &b) const 
    {
        return b.weight < a.weight;
    }
};

template<std::size_t SIZE>
item randomize(array<item, SIZE> items)
{
    int sum = 0;
    std::map<string, double> weights;
    std::random_device rd;
    std::mt19937 gen(rd());
    std::uniform_real_distribution<> dis(0, 1);
    double seed = dis(gen);

    for (item current : items) 
    {
        sum += current.weight;
    }

    for (item current : items) 
    {
        weights[current.name] = (double)current.weight / sum;
    }

    std::sort(items.begin(), items.end(), descending());

    for (item current : items) 
    {
        if (seed < weights[current.name]) return current;
    }

    return items[items.size() - 1];
}

int main() 
{
    array<item, 2> players = 
    {{
        { "michael", 10 },
        { "james", 100 }
    }};

    item player = randomize(players);
    cout << player.name << endl;

    return 0;
}