Example: Reusable Timer Function in C++

// Reusable Timer Function
#include <iostream>
#include <chrono>
#include <functional> // For std::function
#include <vector>
#include <numeric> // For std::iota

using namespace std;

// User-defined material: Function to sum elements of a vector
long long sumVectorElements(const vector<int>& vec) {
    long long sum = 0;
    for (int x : vec) {
        sum += x;
    }
    return sum;
}

// Reusable timing function
template <typename Func>
chrono::microseconds measureExecutionTime(Func func) {
    auto start = chrono::high_resolution_clock::now();
    func(); // Execute the passed function
    auto end = chrono::high_resolution_clock::now();
    return chrono::duration_cast<chrono::microseconds>(end - start);
}

int main() {
    cout << "--- Reusable Timer Function Example ---" << endl;

    vector<int> numbers(1000000);
    iota(numbers.begin(), numbers.end(), 0); // Fill with 0, 1, ..., 999999

    // Timing sumVectorElements directly
    cout << "Timing sumVectorElements..." << endl;
    chrono::microseconds duration_sum_vec = measureExecutionTime([&]() {
        long long result = sumVectorElements(numbers);
        // Avoid optimizing out result by potentially using it
        if (result == -1) { /* dead code */ } 
    });
    cout << "sumVectorElements took: " << duration_sum_vec.count() << " microseconds." << endl;

    // Timing a lambda that performs some other task
    cout << "\nTiming a custom lambda (vector sorting)..." << endl;
    vector<int> random_numbers = {5, 2, 9, 1, 7, 3, 8, 4, 6, 0};
    chrono::microseconds duration_sort = measureExecutionTime([&]() {
        sort(random_numbers.begin(), random_numbers.end());
    });
    cout << "Sorted vector in: " << duration_sort.count() << " microseconds." << endl;

    return 0;
}