Reorganize List-to-array conversion

src/sphere/List.h

@@ -41,19 +41,14 @@ template<class T> class List {
    *
    * b = List<int>();
    */
-  List(int size = 1) {
-    this->size = size;
-    element* p_prev = NULL;
-    T value = (T)0;
-    current = new element;
-    current->value = value;
-    current->p_prev = p_prev;
-    p_prev = current;
-    first = current;
+  List(int length = 1) {
+    size = length;
+    first = new element;
+    first->p_prev = NULL;
+    element *current = first;
+    element *p_prev = first;
     for (int i = 1; i < size; i++) {
-      T value;
       current = new element;
-      current->value = value;
       current->p_prev = p_prev;
       p_prev = current;
     }
@@ -107,6 +102,10 @@ template<class T> class List {
     return current->value;
   }
 
+  int length() {
+    return size;
+  }
+
   /*! \fn set(int, T)
    * \brief Set an element by index and value.
    *
@@ -141,8 +140,8 @@ template<class T> class List {
   T* to_array() {
     T *result = new T[size];
     current = last;
-    for (int i = size - 1; i > 0; i--) {
-      result[i] = current->value;
+    for (int i = size; i > 0; i--) {
+      result[i - 1] = current->value;
       current = current->p_prev;
     }
     return result;