[container] Implement LinkedList as std::list

Author: chris-durand

src/modm/container/doubly_linked_list.hpp

@@ -35,6 +35,7 @@ namespace modm
 	public:
 		using const_iterator = std::list<T>::const_iterator;
 		using iterator = std::list<T>::iterator;
+		using Size = std::size_t;
 
 		DoublyLinkedList(const Allocator& allocator = Allocator())
 			: data_{std::move(allocator)}
@@ -63,10 +64,11 @@ namespace modm
 		}
 
 		/// Insert at the end of the list
-		void
+		bool
 		append(const T& value)
 		{
 			data_.push_back(value);
+			return true;
 		}
 
 		/// Remove the first entry
@@ -82,6 +84,12 @@ namespace modm
 			data_.pop_back();
 		}
 
+		T&
+		getFront()
+		{
+			return data_.front();
+		}
+
 		/**
 		 * \return the first node in the list
 		 */
@@ -91,6 +99,12 @@ namespace modm
 			return data_.front();
 		}
 
+		T&
+		getBack()
+		{
+			return data_.back();
+		}
+
 		/**
 		 * \return the last node in the list
 		 */
@@ -100,7 +114,6 @@ namespace modm
 			return data_.back();
 		}
 
-	public:
 		/**
 		 * Returns a read/write iterator that points to the first element in the
 		 * list.  Iteration is done in ordinary element order.
@@ -153,8 +166,33 @@ namespace modm
 		iterator
 		erase(iterator position)
 		{
-			return data_.erase(position);
+			if (position != data_.end()) {
+				return data_.erase(position);
+			} else {
+				return data_.end();
+			}
+		}
+
+		/**
+		 * Insert data after position iterator.
+		 *
+		 * This behavior is compatible with modm::LinkedList but different
+		 * compared to std::list which inserts before the position iterator
+		 * argument.
+		 */
+		bool
+		insert(iterator position, const T& value)
+		{
+			if (position == data_.end()) {
+				data_.push_back(value);
+			} else {
+				data_.insert(std::next(position), value);
+			}
+			return true;
 		}
+
+	private:
+		std::list<T, Allocator> data_;
 	};
 }
 

src/modm/container/linked_list.hpp

@@ -4,6 +4,7 @@
  * Copyright (c) 2012, Niklas Hauser
  * Copyright (c) 2013-2014, Sascha Schade
  * Copyright (c) 2015, Kevin Läufer
+ * Copyright (c) 2023, Christopher Durand
  *
  * This file is part of the modm project.
  *
@@ -16,9 +17,7 @@
 #ifndef	MODM_LINKED_LIST_HPP
 #define	MODM_LINKED_LIST_HPP
 
-#include <stdint.h>
-#include <iterator>
-#include <modm/utils/allocator.hpp>
+#include <modm/container/doubly_linked_list.hpp>
 
 namespace modm
 {
@@ -34,210 +33,31 @@ namespace modm
 	 *
 	 * \author	Fabian Greif
 	 * \ingroup	modm_container
+	 *
+	 * \todo TODO: implementated as doubly-linked list
+	 * 		 std::forward_list does not save both front and back pointers.
+	 * 		 This would make operations in xpcc very inefficient.
 	 */
-	template <typename T, typename Allocator = allocator::Dynamic<T> >
-	class LinkedList
+	template <typename T, typename Allocator = std::allocator<T>>
+	class LinkedList : public DoublyLinkedList<T, Allocator>
 	{
 	public:
-		typedef std::size_t Size;
-
-	public:
-		LinkedList(const Allocator& allocator = Allocator());
-
-		~LinkedList();
-
-		/// check if there are any nodes in the list
-		inline bool
-		isEmpty() const;
-
-		/**
-		 * \brief	Get number of elements
-		 *
-		 * \warning	This method is slow because it has to iterate through
-		 * 			all elements.
-		 */
-		std::size_t
-		getSize() const;
-
-		/// Insert in front
-		bool
-		prepend(const T& value);
-
-		/// Insert at the end of the list
-		bool
-		append(const T& value);
-
-		/// Remove the first entry
-		void
-		removeFront();
-
-		/**
-		 * \return the first node in the list
-		 */
-		inline const T&
-		getFront() const;
-
-		inline T&
-		getFront();
+		using DoublyLinkedList<T, Allocator>::DoublyLinkedList;
+		using iterator = DoublyLinkedList<T, Allocator>::iterator;
 
-		/**
-		 * \return the last node in the list
-		 */
-		inline const T&
-		getBack() const;
-
-		inline T&
-		getBack();
-
-		/**
-		 * \brief	Remove all elements form the list
-		 */
-		void
-		removeAll();
-
-	protected:
-		struct Node
-		{
-			T value;
-			Node *next;
-		};
-
-		// The stored instance is not actually of type Allocator. Instead we
-		// rebind the type to Allocator<Node<T>>. Node<T> is not the same
-		// size as T (it's one pointer larger), and specializations on T may go
-		// unused because Node<T> is being bound instead.
-		typedef typename Allocator::template rebind< Node >::other NodeAllocator;
-
-		NodeAllocator nodeAllocator;
-
-		Node *front;
-		Node *back;
-
-	public:
-		#pragma GCC diagnostic push
-		#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-		/**
-		 * \brief	Forward iterator
-		 */
-		class iterator : public std::iterator<std::forward_iterator_tag, T>
+		iterator
+		remove(const iterator& position)
 		{
-			friend class LinkedList;
-			friend class const_iterator;
-
-		public:
-			/// Default constructor
-			iterator();
-			iterator(const iterator& other);
+			return this->erase(position);
+		}
 
-			iterator& operator = (const iterator& other);
-			iterator& operator ++ ();
-			bool operator == (const iterator& other) const;
-			bool operator != (const iterator& other) const;
-			T& operator * ();
-			T* operator -> ();
-
-		private:
-			iterator(Node* node);
-
-			Node* node;
-		};
-
-		/**
-		 * \brief	forward const iterator
-		 */
-		class const_iterator : public std::iterator<std::forward_iterator_tag, T>
+		void
+		removeAll()
 		{
-			friend class LinkedList;
-
-		public:
-			/// Default constructor
-			const_iterator();
-
-			/**
-			 * \brief	Copy construtor
-			 *
-			 * Used to convert a normal iterator to a const iterator.
-			 * The other way is not possible.
-			 */
-			const_iterator(const iterator& other);
-
-			/**
-			 * \brief	Copy construtor
-			 */
-			const_iterator(const const_iterator& other);
-
-			const_iterator& operator = (const const_iterator& other);
-			const_iterator& operator ++ ();
-			bool operator == (const const_iterator& other) const;
-			bool operator != (const const_iterator& other) const;
-			const T& operator * () const;
-			const T* operator -> () const;
-
-		private:
-			const_iterator(Node* node);
-			// TODO: this should acutally be a node that points to a const
-			// value, but since all access is const, this does not really make
-			// a difference
-			Node* node;
-		};
-		#pragma GCC diagnostic pop
-
-		/**
-		 * Returns a read/write iterator that points to the first element in      the
-		 * list.  Iteration is done in ordinary element order.
-		 */
-		iterator
-		begin();
-
-		/**
-		 * Returns a read-only (constant) iterator that points to the
-		 * first element in the list.  Iteration is done in ordinary
-		 * element order.
-		 */
-		const_iterator
-		begin() const;
-
-		/**
-		 * Returns a read/write iterator that points one past the last
-		 * element in the list. Iteration is done in ordinary element
-		 * order.
-		 */
-		iterator
-		end();
-
-		/**
-		 * Returns a read-only (constant) iterator that points one past
-		 * the last element in the list.  Iteration is done in ordinary
-		 * element order.
-		 */
-		const_iterator
-		end() const;
-
-		/**
-		 * \brief	Erase element
-		 *
-		 * Removes a single element from the list container.
-		 * This effectively reduces the list size by one, calling the element's
-		 * destructor before.
-		 */
-		iterator
-		remove(const iterator& position);
-
-		bool
-		insert(const_iterator pos, const T& value);
-
-	private:
-		friend class const_iterator;
-		friend class iterator;
-
-		LinkedList(const LinkedList& other);
-
-		LinkedList&
-		operator = (const LinkedList& other);
+			while (!this->isEmpty()) {
+				this->removeFront();
+			}
+		}
 	};
 }
-
-#include "linked_list_impl.hpp"
-#include "linked_list_iterator_impl.hpp"
-
 #endif	// MODM_LINKED_LIST_HPP