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

int main() {
    const std::vector<int> readings{3, 1, 4, 1, 5};
    int threshold{3};
    const auto by_value = [threshold](int value) { return value >= threshold; };
    const auto by_reference = [&threshold](int value) { return value >= threshold; };
    threshold = 5;
    std::cout << std::count_if(readings.begin(), readings.end(), by_value) << '\n';
    std::cout << std::count_if(readings.begin(), readings.end(), by_reference) << '\n';
    return 0;
}