:(

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

using namespace std;

struct Bar{
    uint val;
    uint some_other_val = 0;

    Bar(const uint & val){
        this->val = val;
    }

    void update(const uint & other_val){
        this->some_other_val += other_val;
    }

    bool operator=(const uint & other_val){
        return this->val == other_val;
    }
};


void do_some_stuff(const uint & val, const uint & update, vector<Bar> & foo){

    Bar bar;

    auto it = find(begin(foo), end(foo), val);
    if (it == end(foo)){
        bar = Bar(val);
        foo.emplace_back(bar);
    }
    else
        bar = *it;

    bar.update(update);
}


int main(){

    vector<Bar> foo = {Bar(3), Bar(4)};
    do_some_stuff(4, 22, foo);
    do_some_stuff(5, 22, foo);

    cout << ":(" << endl;
}