Some progress on list (#12)

include/rstl/list.hpp

@@ -9,7 +9,16 @@ namespace rstl {
 template < typename T, typename Alloc = rmemory_allocator >
 class list {
 public:
-  list() : x4_start(&xc_empty), x8_end(&xc_empty), xc_empty(&xc_empty, &xc_empty) {}
+  class iterator;
+  class const_iterator;
+  iterator erase(const iterator &item);
+private:
+  class node;
+  node *erase(const node *item);
+
+public:
+  list()
+  : x4_start(&xc_empty), x8_end(&xc_empty), xc_empty(&xc_empty, &xc_empty) {}
   ~list() {
     node* cur = x4_start;
     while (cur != x8_end) {
@@ -19,6 +28,23 @@ public:
     }
   }
   void push_back(const T&);
+  void clear() {
+    // iterator e = end();
+    iterator cur = begin();
+    while (cur != end()) {
+      cur = erase(cur);
+    }
+    // node *e = x8_end;
+    // node *cur = x4_start;
+    // while (cur != e) {
+    //   cur = erase(cur);
+    // }
+  }
+
+  iterator begin() { return iterator(x4_start); }
+  const_iterator begin() const { return const_iterator(x4_start); }
+  iterator end() { return iterator(x8_end); }
+  const_iterator end() const { return const_iterator(x8_end); }
 
 private:
   struct node {
@@ -34,15 +60,70 @@ private:
     node* get_prev() const { return x0_prev; }
     node* get_next() const { return x4_next; }
     T* get_value() { return x8_item; }
+    const T* get_value_const() const { return x8_item; }
 
     // todo set_next / set_prev
   };
 
+public:
+  class const_iterator {
+  public:;
+    typedef T* value_type;
+
+    const_iterator() : current(nullptr) {}
+    const_iterator(const node *begin) : current(begin) {}
+    const_iterator& operator++() {
+      this->current = this->current->x4_next;
+      return *this;
+    }
+    const_iterator operator++(int) const { return const_iterator(this->current->x4_next); }
+    const_iterator& operator--() {
+      this->current = this->current->x0_prev;
+      return *this;
+    }
+    const_iterator operator--(int) const { return const_iterator(this->current->x0_prev); }
+    const T* get_pointer() const { return current->x8_item; }
+    const T& operator*() const { return *current->x8_item; }
+    const T* operator->() const { return current->x8_item; }
+    bool operator==(const const_iterator& other) const { return current == other.current; }
+    bool operator!=(const const_iterator& other) const { return current != other.current; }
+
+  protected:
+    const node* current;
+  };
+
+  class iterator: const_iterator {
+  public:
+    typedef T* value_type;
+
+    iterator() : const_iterator(nullptr) {}
+    iterator(node *begin) : const_iterator(begin) {}
+    iterator& operator++() {
+      this->current = this->current->x4_next;
+      return *this;
+    }
+    iterator operator++(int) { return const_iterator(this->current->x4_next; }
+    iterator& operator--() {
+      this->current = this->current->x0_prev;
+      return *this;
+    }
+    iterator operator--(int) { return iterator(this->curent->x0_prev); }
+    T* get_pointer() const { return current->get_value(); }
+    T& operator*() const { return *current->get_value(); }
+    T* operator->() const { return current->get_value(); }
+    bool operator==(const iterator& other) const { return current == other.current; }
+    bool operator!=(const iterator& other) const { return current != other.current; }
+  protected:
+    node* current;
+  };
+
+private:
   Alloc x0_allocator;
   node* x4_start;
   node* x8_end;
   node xc_empty;
 };
+
 } // namespace rstl
 
 #endif // _RSTL_LIST