Smart Pointers

// Always use make_unique() to create a unique_ptr
void processData(Simple* simple) {}
auto smartPtr = make_unique<Simple>();
processData(smartPtr.get()); // call get() to get the underlying pointer
smartPtr.reset(); // Free resource and set to nullptr
smartPtr.reset(new Simple()); // free resource and set to a new
smartPtr.release() // return the underlying pointer to the resource and then set the smart pointer to nullptr.

int* malloc_int(int value)
{
    int* p = (int*)malloc(sizeof(int));
    *p = value;
    return p;
}
int main()
{
    // The template type parameter should be the type of a pointer to a function,
    // so an additional * is appended, as in decltype(free)*
    unique_ptr<int, decltype(free)*> myIntSmartPtr(malloc_int(42), free);
    return 0;
}

// Always use make_shared() to create a shared_ptr.
auto smpt = make_shared<Simple>();
// Also support the get() and reset() methods, when calling reset(), due to reference counting, 
// the underlying resource is only freed when the last shared_ptr is destroyed or reset.
// Not support release(), you can use use_count() to retrieve the number of shared_ptr instances that are sharing the same resource.