How do I optimize small object allocations in high-performance C++?

#include <iostream>
#include <memory>
#include <vector>

class SmallObject {
public:
    int data[16]; // Small object with fixed size
};

class ObjectPool {
private:
    std::vector<SmallObject> pool;
    size_t index;

public:
    ObjectPool(size_t size) : pool(size), index(0) {}

    SmallObject* allocate() {
        if (index < pool.size()) {
            return &pool[index++];
        }
        return nullptr; // No more objects available
    }

    void deallocate(SmallObject* obj) {
        // Logic for deallocation if needed
        // In this simple example, we do nothing
    }
};

int main() {
    ObjectPool pool(10); // Pool for 10 small objects

    SmallObject* obj1 = pool.allocate();
    if (obj1) {
        std::cout << "Allocated SmallObject at " << obj1 << std::endl;
    }

    // Use obj1...

    pool.deallocate(obj1); // Deallocate if required
    return 0;
}