fixed iterators and iterator usage

src/list.hh

@@ -8,11 +8,21 @@
 
 namespace phundrak {
 
-using size_type = size_t;
+  using size_type = size_t;
 
-template <class T, class Allocator = std::allocator<T>> class list {
+  template <class T, class Allocator = std::allocator<T>> class list {
+
+  public:
+    class iterator;
+    class reverse_iterator;
+    class const_iterator;
+    class const_reverse_iterator;
+    // using const_iterator = const iterator;
+    // using const_reverse_iterator = const reverse_iterator;
+
+  private:
+    // data structure ///////////////////////////////////////////////////////////
 
-private:
     struct cell {
       cell() = default;
       explicit cell(const T &value) : x{value}, p{nullptr}, n{nullptr} {}
@@ -31,7 +41,7 @@ private:
       }
       cell &operator=(cell &&other) {
         std::swap(x, other.x);
-      std::swap(other.n, n);
+        std::swap(n, other.n);
         std::swap(p, other.p);
         return *this;
       }
@@ -40,25 +50,21 @@ private:
       T x;
     };
 
+    // members //////////////////////////////////////////////////////////////////
+
     cell *sentry;
     const Allocator alloc_;
 
-public:
-  class iterator;
-  class reverse_iterator;
-  using const_iterator = const iterator;
-  using const_reverse_iterator = const reverse_iterator;
-
+  public:
     /////////////////////////////////////////////////////////////////////////////
     //                             Member functions                            //
     /////////////////////////////////////////////////////////////////////////////
 
     // Constructors /////////////////////////////////////////////////////////////
 
-  list() : list{Allocator()}, sentry{new cell} {}
+    list() : list{Allocator()}, sentry{new cell{}} {}
 
-  explicit list(const Allocator &alloc) : alloc_(alloc) {
-    sentry = new cell{};
+    explicit list(const Allocator &alloc) : sentry{new cell{}}, alloc_{alloc} {
       sentry->p = sentry;
       sentry->n = sentry;
     }
@@ -270,11 +276,11 @@ public:
     // erase ////////////////////////////////////////////////////////////////////
 
     iterator erase(const_iterator pos) {
-    pos->p->n = pos->n;
-    pos->n->p = pos->p;
-    pos->n = nullptr;
-    pos->p = nullptr;
-    cell *todel = pos;
+      pos.it->p->n = pos.it->n;
+      pos.it->n->p = pos.it->p;
+      pos.it->n = nullptr;
+      pos.it->p = nullptr;
+      cell *todel = pos.it;
       ++pos;
       delete todel;
       return pos;
@@ -638,14 +644,14 @@ public:
     // unique ///////////////////////////////////////////////////////////////////
 
     void unique() {
-    for(auto elem = sentry->n; elem->n != sentry; elem = elem->n)
-      if(elem->x == elem->n->x)
-        erase(iterator{elem->n});
+      for (auto elem = sentry->n; elem->n != sentry; elem = elem->n)
+        while (elem->x == elem->n->x)
+          erase(const_iterator{elem->n});
     }
 
-  template<class BinaryPredicate> void unique(BinaryPredicate p) {
-    for(auto elem = sentry->n; elem->n != sentry; elem = elem->n)
-      if(p(elem, elem->n))
+    template <class BinaryPredicate> void unique(BinaryPredicate p) {
+      for (auto elem = sentry->n; elem->n != sentry; elem = elem->n)
+        while (p(elem, elem->n))
           erase(iterator{elem->n});
     }
 
@@ -679,7 +685,9 @@ public:
         return *this;
       }
 
-    ~iterator() {}
+      ~iterator() {
+        // delete it;
+      }
 
       iterator &operator++() { // ++i
         it = it->n;
@@ -714,16 +722,28 @@ public:
       bool operator!=(const iterator &other) { return other.it != it; }
       bool operator!=(iterator &&other) { return other.it != it; }
 
-    T& operator*() { return it->x; }
+      T &operator*() { return it->x; }
+
+      friend class list;
     };
 
-  class reverse_iterator : protected iterator {
+    class const_iterator : public iterator {
+    public:
+      const_iterator() : iterator() {}
+      explicit const_iterator(cell *point) : iterator{point} {}
+      explicit const_iterator(const iterator &other) : iterator{other} {}
+      const_iterator(const const_iterator &other) : iterator{other} {}
+      explicit const_iterator(iterator &&other) : iterator{std::move(other)} {}
+      const_iterator(const_iterator &&other) : iterator{std::move(other)} {}
+
+      const T &operator*() { return this->it->x; }
+    };
+
+    class reverse_iterator : public iterator {
     public:
       reverse_iterator() : iterator() {}
-    explicit reverse_iterator(T *point) : iterator(point) {}
-
+      explicit reverse_iterator(cell *point) : iterator(point) {}
       reverse_iterator(const reverse_iterator &other) : iterator(other) {}
-
       reverse_iterator(reverse_iterator &&other) : iterator(std::move(other)) {}
 
       reverse_iterator &operator++() {
@@ -750,6 +770,19 @@ public:
 
       ~reverse_iterator() {}
     };
-};
+
+    class const_reverse_iterator : public reverse_iterator {
+    public:
+      const_reverse_iterator() : reverse_iterator() {}
+      explicit const_reverse_iterator(cell *point) : reverse_iterator{point} {}
+      explicit const_reverse_iterator(const reverse_iterator &other)
+        : reverse_iterator{other} {}
+      const_reverse_iterator(const const_reverse_iterator &other)
+        : reverse_iterator{other} {}
+      explicit const_reverse_iterator(reverse_iterator &&other)
+        : reverse_iterator{other} {}
+      virtual ~const_reverse_iterator() { ~reverse_iterator(); }
+    };
+  };
 
 } // namespace phundrak

src/test.cc

@@ -1,25 +1,29 @@
 #include "list.hh"
 #include "vector.hh"
-#include <cstdio>
+#include <iostream>
 
 using namespace phundrak;
+using std::cout;
 
 int main(void) {
 
-  printf("Hello 1!\n");
   list<char> test {'C', 'a', 'r', 't', 'i', 'e', 'r'};
-  printf("Hello !\n");
 
-  for(auto c : test) {
-    printf("%c\n", c);
-  }
+  for(auto c : test)
+    cout << c << "  ";
+
+  cout << "\n";
 
   list<int> test_unique {1,1,1,1,1,2,2,2,3,3,3,4,4,1,1,5,1,2,1,1,3,3,3};
   printf("Elements before unique():\n");
   for(const auto& elem : test_unique)
-    printf("%2d,", elem);
+    cout << elem << "  ";
 
+  cout << "\n";
   test_unique.unique();
+  for(const auto& elem : test_unique)
+    cout << elem << "  ";
+  cout << "\n";
 
   return 0;
 }