Vectors in Arduino

Question

I am making a vector of "waypoints" on the Arduino. Each waypoint is an object. The Arduino will obviously need to store multiple waypoints for waypoint navigation. But instead of storing these waypoints in a standard preprogrammed array, the user will need to be able to add, remove waypoints and move them around. Unfortunately the Arduino does not offer a vector type as a built-in library.

I am currently contemplating two options:

1. In Container for objects like C++ 'vector'?, someone posted a general purpose library. It does not contain any index deletion, or movement operations. But it does contain some memory management strategies.

2. I have used malloc, dealloc, calloc in the past. But I do not like that option at all, especially with classes. But is this a better option in my senario?

Which one is a better path to go down?

Answer 1

Standard C++ for Arduino might be an option. It lets you use the STL vector in Arduino.

Answer 2

You can write this LinkedList template class and simply call it wherever you want :

#ifndef LinkedList_hpp #define LinkedList_hpp   template <class T> class ListNode {   public:     T element;     ListNode* next;     ListNode* prev;      ListNode(T element, ListNode* prev, ListNode* next) : element(element)     {       this->next = next;       this->prev = prev;     }; };  template <class T> class LinkedList  {   private:     int length;     ListNode<T>* head;     ListNode<T>* tail;     ListNode<T>* curr;   public:     LinkedList();     LinkedList(const LinkedList<T>&);     ~LinkedList();     T& getCurrent();     T& First() const;     T& Last() const;     int getLength();     void Append(T);     void DeleteLast();     void DeleteFirst();     void DeleteCurrent();     bool next();     bool moveToStart();     bool prev();     void Delete(T&);     bool Search(T);     void Clear();     void PutFirstToLast();     void Update(T elem);     LinkedList& operator = (const LinkedList<T>&); };  template <class T> LinkedList<T>::LinkedList() {     length = 0;     head = nullptr;     tail = nullptr;     curr = nullptr; }  template <class T> LinkedList<T>::LinkedList(const LinkedList<T> & list) {     length = 0;     head = nullptr;     tail = nullptr;     curr = nullptr;      ListNode<T> * temp = list.head;      while(temp != nullptr)     {         Append(temp->element);         temp = temp->next;     } }  template <class T> LinkedList<T> & LinkedList<T>::operator=(const LinkedList<T> & list) {     Clear();      ListNode<T> * temp = list.head;      while(temp != nullptr)     {         Append(temp->element);         temp = temp->next;     }      return *this; }  template <class T> LinkedList<T>::~LinkedList() {     Clear(); }  template<class T> T& LinkedList<T>::getCurrent() {   return curr->element; }  template<class T> T& LinkedList<T>::First() const {   return head->element; }  template<class T> T& LinkedList<T>::Last() const {   return tail->element; }  template<class T> int LinkedList<T>::getLength() {   return length; }  template <class T> void LinkedList<T>::Append(T element) {     ListNode<T> * node = new ListNode<T>(element, tail, nullptr);      if(length == 0)         curr = tail = head = node;     else {         tail->next = node;         tail = node;     }      length++;  }  template <class T> void LinkedList<T>::DeleteLast() {     if(length == 0)       return;     curr = tail;     DeleteCurrent(); }  template <class T> void LinkedList<T>::DeleteFirst() {     if(length == 0)       return;     curr = head;     DeleteCurrent(); }  template <class T> bool LinkedList<T>::next() {     if(length == 0)         return false;      if(curr->next == nullptr)         return false;      curr = curr->next;     return true; }  template <class T> bool LinkedList<T>::moveToStart() {     curr = head;     return length != 0; }  template<class T> bool LinkedList<T>::prev() {     if(length == 0)         return false;      if(curr->prev != nullptr)         return false;      curr = curr->prev;     return true; }  template <class T> void LinkedList<T>::Delete(T & elem) {     if(Search(elem))         DeleteCurrent(); }  template <class T> void LinkedList<T>::DeleteCurrent() {     if(length == 0)         return;     length--;     ListNode<T> * temp = curr;      if(temp->prev != nullptr)         temp->prev->next = temp->next;     if(temp->next != nullptr)         temp->next->prev = temp->prev;      if(length == 0)         head = curr = tail = nullptr;     else if(curr == head)         curr = head = head->next;     else if(curr == tail)         curr = tail = tail->prev;     else         curr = curr->prev;       delete temp; }  template <class T> bool LinkedList<T>::Search(T elem) {     if(length == 0)         return false;     if(moveToStart())         do {             if(curr->element == elem)                 return true;         } while (next());     return false; }  template <class T> void LinkedList<T>::PutFirstToLast() {   if(length < 2)     return;   ListNode<T>* temp = head->next;   head->next->prev = nullptr;   head->next = nullptr;   head->prev = tail;   tail->next = head;   tail = head;   head = temp; }  template <class T> void LinkedList<T>::Update(T elem) {     if(Search(elem))         curr->element = elem; }  template <class T> void LinkedList<T>::Clear() {     if(length == 0)         return;     ListNode<T> * temp = head;      while(temp != nullptr)     {         head = head->next;         delete temp;         temp = head;     }      head = curr = tail = nullptr;      length = 0;  }   #endif 

Use this class as follow:

LinkedList<int> list;  list.Append(1); list.Append(2); list.Append(3); list.Append(4);  int my_integer;  if(list.moveToStart())     do{         my_integer = list.getCurrent();     }while(list.next());