Example: RAII Timer Class in C++

// RAII Timer Class
#include <iostream>
#include <chrono>
#include <thread> // For std::this_thread::sleep_for
#include <string> // For message

using namespace std;

class ScopedTimer {
public:
    explicit ScopedTimer(const string& message)
        : m_message(message), m_start(chrono::high_resolution_clock::now()) {
        // Optional: print start message
        // cout << "Timer '" << m_message << "' started." << endl;
    }

    ~ScopedTimer() {
        auto end = chrono::high_resolution_clock::now();
        auto duration = chrono::duration_cast<chrono::microseconds>(end - m_start);
        cout << "Timer '" << m_message << "' finished in "
             << duration.count() << " microseconds." << endl;
    }

private:
    string m_message;
    chrono::high_resolution_clock::time_point m_start;
};

// User-defined material: A function to simulate complex calculations
void complexCalculation(int seconds) {
    long long result = 0;
    for (int i = 0; i < seconds * 100000; ++i) { // Simulate work for 'seconds'
        result += i * i;
    }
    // Prevent optimization
    if (result == -1) { /* dead code */ }
    this_thread::sleep_for(chrono::seconds(seconds)); // Ensure visible duration
}


int main() {
    cout << "--- RAII Timer Class Example ---" << endl;

    cout << "Starting main tasks..." << endl;

    // Task 1: Scoped timer for a block of code
    {
        ScopedTimer timer_block("Complex Loop");
        cout << "Inside complex loop block..." << endl;
        for (int i = 0; i < 500000; ++i) {
            // Some heavy computation
            volatile int temp = i * i; // Use volatile to prevent optimization
            if (temp % 100000 == 0) {
                // cout << "." << flush; // Optional progress indicator
            }
        }
        cout << "Exiting complex loop block." << endl;
    } // timer_block goes out of scope here, duration is printed

    cout << "\nContinuing with other tasks..." << endl;

    // Task 2: Scoped timer for a function call
    {
        ScopedTimer timer_function("Function Call (complexCalculation)");
        complexCalculation(1); // Call our user-defined function
    } // timer_function goes out of scope here

    cout << "\nMain tasks completed." << endl;

    return 0;
}