stlExamplesDraft

#include <iostream>
#include <vector>
#include <algorithm>
#include <numeric>

template <typename T>
class gen
{
    T cnt;
public:
    gen(T val): cnt{val} {};
    gen() : gen{0} {};
    T operator()() { return cnt++; };
};


template <typename T>
class mul
{
    T multipler;
public:
    mul(T val): multipler{val} {};
    mul() : mul{0} {};
    void operator()(T& arg) { arg *= multipler; };
};

int main()
{
//  std::pair p{std::make_pair(0, "Apple")};
//  std::cout << p.first << ' ' << p.second << '\n';
    std::vector<int> arr{1,2,4,1,5,6,1,7,8,1,9,1};


    //std::partial_sum(arr.begin(), arr.end(), std::ostream_iterator<int>(std::cout , " "));
    //std::cout << std::accumulate(arr.begin(), arr.end(),1,[](auto a, auto b){ return a*b;}) << '\n';

    auto curr{arr.begin()};
    while ( (curr = std::find(curr,arr.end(),1)) != arr.end())
    {
        std::cout << std::distance(arr.begin(),curr) << '\n';
        curr++;
    }

    gen<int> g{1};
    mul<int> m{3};

    std::generate(arr.begin(), arr.end(),g);
    std::copy(arr.begin(), arr.end(),std::ostream_iterator<int>(std::cout, " "));
    std::for_each(arr.begin(), arr.end(),m);
    std::copy(arr.begin(), arr.end(),std::ostream_iterator<int>(std::cout, " "));
}