[tutorial] filter (extract list of vals on a condition)

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

template <typename Collection,typename Predicate>
Collection filter(Collection col, Predicate predicate) {
    auto fnCol = filterNot(col,[predicate](typename Collection::value_type i) { return !predicate(i);});
    return fnCol;
}

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 filter");
    auto condition = [](int value) {
        return value > 30;
    };
    auto filterCol = filter(col,condition);
    std::copy(filterCol.begin(), filterCol.end(), std::ostream_iterator<int>(std::cout, " "));

    return 0;
}