[tutorial] if_exist (check if val exists in collection)

#include <algorithm>
#include <iostream>
#include <vector>
#include <iomanip>
#include <functional>
#include <iterator>

template<typename Collection, typename Condition>
bool if_exist(Collection col, Condition con) {
    auto exist = std::find_if(col.begin(), col.end(), con);
    return exist != col.end();
}

int main()
{
    auto println = [](const char *message) { std::cout << "\n" << message << '\n'; };
    std::vector<int> col{ 23, 23, 37, 42, 23, 23, 37 };

    println("running exist() function");
    auto check_func = [] (int val) {
        return val == 20;
    };
    std::cout << if_exist(col, check_func)  << '\n';

    return 0;
}