How Do You Implement Custom Memory Allocators in C++?

Custom memory allocators in C++ allow for more control over memory management. They can optimize allocation patterns specific to application needs. Custom allocators are useful for performance tuning and managing complex data structures.

Example of a custom allocator:

#include 
#include 

template 
class MyAllocator : public std::allocator {
public:
    T* allocate(size_t n) {
        std::cout << "Allocating " << n << " elements." << std::endl;
        return std::allocator::allocate(n);
    }
    void deallocate(T* p, size_t n) {
        std::cout << "Deallocating " << n << " elements." << std::endl;
        std::allocator::deallocate(p, n);
    }
};

int main() {
    std::vector> vec;
    vec.push_back(10);
    return 0;
}