diff --git a/doc/Makefile b/doc/Makefile
index b303a785..35077b81 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -54,7 +54,7 @@ doxygen: create_output create_links
 	gsed -i 's@< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberFloatType, AllocatorType >@@g' html/*.html
 	gsed -i 's@< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberFloatType, AllocatorType >@@g' html/*.html
 
-upload: doxygen check_output
+upload: clean doxygen check_output
 	cd html ; ../git-update-ghpages nlohmann/json
 	rm -fr html
 	open http://nlohmann.github.io/json/
diff --git a/src/json.hpp b/src/json.hpp
index 8922f96e..9511f02c 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -172,14 +172,17 @@ class basic_json
     /// the type of an element const pointer
     using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer;
 
+    // forward declaration
+    template<typename Base> class json_reverse_iterator;
+
     /// an iterator for a basic_json container
     class iterator;
     /// a const iterator for a basic_json container
     class const_iterator;
     /// a reverse iterator for a basic_json container
-    class reverse_iterator;
+    using reverse_iterator = json_reverse_iterator<typename basic_json::iterator>;
     /// a const reverse iterator for a basic_json container
-    class const_reverse_iterator;
+    using const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>;
 
     /// @}
 
@@ -4863,522 +4866,6 @@ class basic_json
     };
 
   public:
-    /// a random access iterator for the basic_json class
-    class iterator : public std::iterator<std::random_access_iterator_tag, basic_json>
-    {
-        // allow basic_json class to access m_it
-        friend class basic_json;
-
-      public:
-        /// the type of the values when the iterator is dereferenced
-        using value_type = typename basic_json::value_type;
-        /// a type to represent differences between iterators
-        using difference_type = typename basic_json::difference_type;
-        /// defines a pointer to the type iterated over (value_type)
-        using pointer = typename basic_json::pointer;
-        /// defines a reference to the type iterated over (value_type)
-        using reference = typename basic_json::reference;
-        /// the category of the iterator
-        using iterator_category = std::bidirectional_iterator_tag;
-
-        /// default constructor
-        iterator() = default;
-
-        /// constructor for a given JSON instance
-        iterator(pointer object) : m_object(object)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = typename object_t::iterator();
-                    break;
-                }
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = typename array_t::iterator();
-                    break;
-                }
-                default:
-                {
-                    m_it.primitive_iterator = primitive_iterator_t();
-                    break;
-                }
-            }
-        }
-
-        /// copy constructor
-        iterator(const iterator& other) noexcept
-            : m_object(other.m_object), m_it(other.m_it)
-        {}
-
-        /// copy assignment
-        iterator& operator=(iterator other) noexcept (
-            std::is_nothrow_move_constructible<pointer>::value and
-            std::is_nothrow_move_assignable<pointer>::value and
-            std::is_nothrow_move_constructible<internal_iterator>::value and
-            std::is_nothrow_move_assignable<internal_iterator>::value
-        )
-        {
-            std::swap(m_object, other.m_object);
-            std::swap(m_it, other.m_it);
-            return *this;
-        }
-
-      private:
-        /// set the iterator to the first value
-        void set_begin()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = m_object->m_value.object->begin();
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = m_object->m_value.array->begin();
-                    break;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    // set to end so begin()==end() is true: null is empty
-                    m_it.primitive_iterator.set_end();
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator.set_begin();
-                    break;
-                }
-            }
-        }
-
-        /// set the iterator past the last value
-        void set_end()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = m_object->m_value.object->end();
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = m_object->m_value.array->end();
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator.set_end();
-                    break;
-                }
-            }
-        }
-
-      public:
-        /// return a reference to the value pointed to by the iterator
-        reference operator*()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return m_it.object_iterator->second;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return *m_it.array_iterator;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator.is_begin())
-                    {
-                        return *m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// dereference the iterator
-        pointer operator->()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return &(m_it.object_iterator->second);
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return &*m_it.array_iterator;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator.is_begin())
-                    {
-                        return m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// post-increment (it++)
-        iterator operator++(int)
-        {
-            auto result = *this;
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator++;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator++;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator++;
-                    break;
-                }
-            }
-
-            return result;
-        }
-
-        /// pre-increment (++it)
-        iterator& operator++()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    ++m_it.object_iterator;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    ++m_it.array_iterator;
-                    break;
-                }
-
-                default:
-                {
-                    ++m_it.primitive_iterator;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// post-decrement (it--)
-        iterator operator--(int)
-        {
-            auto result = *this;
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator--;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator--;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator--;
-                    break;
-                }
-            }
-
-            return result;
-        }
-
-        /// pre-decrement (--it)
-        iterator& operator--()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    --m_it.object_iterator;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    --m_it.array_iterator;
-                    break;
-                }
-
-                default:
-                {
-                    --m_it.primitive_iterator;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// comparison: equal
-        bool operator==(const iterator& other) const
-        {
-            // if objects are not the same, the comparison is undefined
-            if (m_object != other.m_object)
-            {
-                throw std::domain_error("cannot compare iterators of different containers");
-            }
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return (m_it.object_iterator == other.m_it.object_iterator);
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return (m_it.array_iterator == other.m_it.array_iterator);
-                }
-
-                default:
-                {
-                    return (m_it.primitive_iterator == other.m_it.primitive_iterator);
-                }
-            }
-        }
-
-        /// comparison: not equal
-        bool operator!=(const iterator& other) const
-        {
-            return not operator==(other);
-        }
-
-        /// comparison: smaller
-        bool operator<(const iterator& other) const
-        {
-            // if objects are not the same, the comparison is undefined
-            if (m_object != other.m_object)
-            {
-                throw std::domain_error("cannot compare iterators of different containers");
-            }
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator< for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return (m_it.array_iterator < other.m_it.array_iterator);
-                }
-
-                default:
-                {
-                    return (m_it.primitive_iterator < other.m_it.primitive_iterator);
-                }
-            }
-        }
-
-        /// comparison: less than or equal
-        bool operator<=(const iterator& other) const
-        {
-            return not other.operator < (*this);
-        }
-
-        /// comparison: greater than
-        bool operator>(const iterator& other) const
-        {
-            return not operator<=(other);
-        }
-
-        /// comparison: greater than or equal
-        bool operator>=(const iterator& other) const
-        {
-            return not operator<(other);
-        }
-
-        /// add to iterator
-        iterator& operator+=(difference_type i)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator+= for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator += i;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator += i;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// subtract from iterator
-        iterator& operator-=(difference_type i)
-        {
-            return operator+=(-i);
-        }
-
-        /// add to iterator
-        iterator operator+(difference_type i)
-        {
-            auto result = *this;
-            result += i;
-            return result;
-        }
-
-        /// subtract from iterator
-        iterator operator-(difference_type i)
-        {
-            auto result = *this;
-            result -= i;
-            return result;
-        }
-
-        /// return difference
-        difference_type operator-(const iterator& other) const
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator- for object iterators");
-                    return 0;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return m_it.array_iterator - other.m_it.array_iterator;
-                }
-
-                default:
-                {
-                    return m_it.primitive_iterator - other.m_it.primitive_iterator;
-                }
-            }
-        }
-
-        /// access to successor
-        reference operator[](difference_type n)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator[] for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return *(m_it.array_iterator + n);
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator == -n)
-                    {
-                        return *m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// return the key of an object iterator
-        typename object_t::key_type key() const
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return m_it.object_iterator->first;
-                }
-
-                default:
-                {
-                    throw std::domain_error("cannot use key() for non-object iterators");
-                }
-            }
-        }
-
-        /// return the key of an iterator
-        reference value()
-        {
-            return operator*();
-        }
-
-      private:
-        /// associated JSON instance
-        pointer m_object = nullptr;
-        /// the actual iterator of the associated instance
-        internal_iterator m_it = internal_iterator();
-    };
-
     /// a const random access iterator for the basic_json class
     class const_iterator : public std::iterator<std::random_access_iterator_tag, const basic_json>
     {
@@ -5874,70 +5361,96 @@ class basic_json
         internal_iterator m_it = internal_iterator();
     };
 
-    /*!
-    @brief a reverse random access iterator for the basic_json class
-
-    The reverse iterator is realized with the `std::reverse_iterator` adaptor.
-    This adaptor does not automatically inherit all functionality from the
-    base iterator class, so some functions need to be explicitly implemented
-    by either delegating them to the base class or by using the `base()`
-    function to access the underlying base iterator.
-
-    The following operators are implicitly inherited:
-
-    - `operator==`, `operator!=`, `operator<`, `operator<=`, `operator>`,
-      `operator>=`
-    - `operator-=`
-    - `operator->`, `operator*`
-    */
-    class reverse_iterator : public std::reverse_iterator<typename basic_json::iterator>
+    /// a random access iterator for the basic_json class
+    class iterator : public const_iterator
     {
       public:
-        /// shortcut to the reverse iterator adaptor
-        using base_iterator = std::reverse_iterator<typename basic_json::iterator>;
+        using base_iterator = const_iterator;
+        using pointer = typename basic_json::pointer;
+        using reference = typename basic_json::reference;
 
-        /// create reverse iterator from iterator
-        reverse_iterator(const typename base_iterator::iterator_type& it)
-            : base_iterator(it) {}
+        /// default constructor
+        iterator() = default;
 
-        /// create reverse iterator from base class
-        reverse_iterator(const base_iterator& it) : base_iterator(it) {}
+        /// constructor for a given JSON instance
+        iterator(pointer object) noexcept : base_iterator(object)
+        {}
+
+        /// copy constructor
+        iterator(const iterator& other) noexcept
+            : base_iterator(other)
+        {}
+
+        /// copy assignment
+        iterator& operator=(iterator other) noexcept(
+            std::is_nothrow_move_constructible<pointer>::value and
+            std::is_nothrow_move_assignable<pointer>::value and
+            std::is_nothrow_move_constructible<internal_iterator>::value and
+            std::is_nothrow_move_assignable<internal_iterator>::value
+        )
+        {
+            base_iterator::operator=(other);
+            return *this;
+        }
+
+        /// return a reference to the value pointed to by the iterator
+        reference operator*()
+        {
+            return const_cast<reference>(base_iterator::operator*());
+        }
+
+        /// dereference the iterator
+        pointer operator->()
+        {
+            return const_cast<pointer>(base_iterator::operator->());
+        }
 
         /// post-increment (it++)
-        reverse_iterator operator++(int)
+        iterator operator++(int)
         {
-            return base_iterator::operator++(1);
+            iterator result = *this;
+            base_iterator::operator++();
+            return result;
         }
 
         /// pre-increment (++it)
-        reverse_iterator& operator++()
+        iterator& operator++()
         {
             base_iterator::operator++();
             return *this;
         }
 
         /// post-decrement (it--)
-        reverse_iterator operator--(int)
+        iterator operator--(int)
         {
-            return base_iterator::operator--(1);
+            iterator result = *this;
+            base_iterator::operator--();
+            return result;
         }
 
         /// pre-decrement (--it)
-        reverse_iterator& operator--()
+        iterator& operator--()
         {
             base_iterator::operator--();
             return *this;
         }
 
         /// add to iterator
-        reverse_iterator& operator+=(difference_type i)
+        iterator& operator+=(difference_type i)
         {
             base_iterator::operator+=(i);
             return *this;
         }
 
+        /// subtract from iterator
+        iterator& operator-=(difference_type i)
+        {
+            base_iterator::operator-=(i);
+            return *this;
+        }
+
         /// add to iterator
-        reverse_iterator operator+(difference_type i) const
+        iterator operator+(difference_type i)
         {
             auto result = *this;
             result += i;
@@ -5945,7 +5458,90 @@ class basic_json
         }
 
         /// subtract from iterator
-        reverse_iterator operator-(difference_type i) const
+        iterator operator-(difference_type i)
+        {
+            auto result = *this;
+            result -= i;
+            return result;
+        }
+
+        difference_type operator-(const iterator& other) const
+        {
+            return base_iterator::operator-(other);
+        }
+
+        /// access to successor
+        reference operator[](difference_type n) const
+        {
+            return const_cast<reference>(base_iterator::operator[](n));
+        }
+
+        /// return the value of an iterator
+        reference value() const
+        {
+            return const_cast<reference>(base_iterator::value());
+        }
+    };
+
+    /// a template for a reverse iterator class
+    template<typename Base>
+    class json_reverse_iterator : public std::reverse_iterator<Base>
+    {
+      public:
+        /// shortcut to the reverse iterator adaptor
+        using base_iterator = std::reverse_iterator<Base>;
+        using reference = typename Base::reference;
+
+        /// create reverse iterator from iterator
+        json_reverse_iterator(const typename base_iterator::iterator_type& it)
+            : base_iterator(it) {}
+
+        /// create reverse iterator from base class
+        json_reverse_iterator(const base_iterator& it) : base_iterator(it) {}
+
+        /// post-increment (it++)
+        json_reverse_iterator operator++(int)
+        {
+            return base_iterator::operator++(1);
+        }
+
+        /// pre-increment (++it)
+        json_reverse_iterator& operator++()
+        {
+            base_iterator::operator++();
+            return *this;
+        }
+
+        /// post-decrement (it--)
+        json_reverse_iterator operator--(int)
+        {
+            return base_iterator::operator--(1);
+        }
+
+        /// pre-decrement (--it)
+        json_reverse_iterator& operator--()
+        {
+            base_iterator::operator--();
+            return *this;
+        }
+
+        /// add to iterator
+        json_reverse_iterator& operator+=(difference_type i)
+        {
+            base_iterator::operator+=(i);
+            return *this;
+        }
+
+        /// add to iterator
+        json_reverse_iterator operator+(difference_type i) const
+        {
+            auto result = *this;
+            result += i;
+            return result;
+        }
+
+        /// subtract from iterator
+        json_reverse_iterator operator-(difference_type i) const
         {
             auto result = *this;
             result -= i;
@@ -5953,7 +5549,7 @@ class basic_json
         }
 
         /// return difference
-        difference_type operator-(const reverse_iterator& other) const
+        difference_type operator-(const json_reverse_iterator& other) const
         {
             return this->base() - other.base();
         }
@@ -5979,97 +5575,6 @@ class basic_json
         }
     };
 
-    /// a const reverse random access iterator for the basic_json class
-    class const_reverse_iterator : public std::reverse_iterator<typename basic_json::const_iterator>
-    {
-      public:
-        /// shortcut to the reverse iterator adaptor
-        using base_iterator = std::reverse_iterator<typename basic_json::const_iterator>;
-
-        /// create reverse iterator from iterator
-        const_reverse_iterator(const typename base_iterator::iterator_type& it)
-            : base_iterator(it) {}
-
-        /// create reverse iterator from base class
-        const_reverse_iterator(const base_iterator& it) : base_iterator(it) {}
-
-        /// post-increment (it++)
-        const_reverse_iterator operator++(int)
-        {
-            return base_iterator::operator++(1);
-        }
-
-        /// pre-increment (++it)
-        const_reverse_iterator& operator++()
-        {
-            base_iterator::operator++();
-            return *this;
-        }
-
-        /// post-decrement (it--)
-        const_reverse_iterator operator--(int)
-        {
-            return base_iterator::operator--(1);
-        }
-
-        /// pre-decrement (--it)
-        const_reverse_iterator& operator--()
-        {
-            base_iterator::operator--();
-            return *this;
-        }
-
-        /// add to iterator
-        const_reverse_iterator& operator+=(difference_type i)
-        {
-            base_iterator::operator+=(i);
-            return *this;
-        }
-
-        /// add to iterator
-        const_reverse_iterator operator+(difference_type i) const
-        {
-            auto result = *this;
-            result += i;
-            return result;
-        }
-
-        /// subtract from iterator
-        const_reverse_iterator operator-(difference_type i) const
-        {
-            auto result = *this;
-            result -= i;
-            return result;
-        }
-
-        /// return difference
-        difference_type operator-(const const_reverse_iterator& other) const
-        {
-            return this->base() - other.base();
-        }
-
-        /// access to successor
-        const_reference operator[](difference_type n) const
-        {
-            return *(this->operator+(n));
-        }
-
-        /// return the key of an object iterator
-        typename object_t::key_type key() const
-        {
-            auto it = --this->base();
-            return it.key();
-        }
-
-        /// return the value of an iterator
-        const_reference value() const
-        {
-            auto it = --this->base();
-            return it.operator * ();
-        }
-    };
-
-
   private:
     //////////////////////
     // lexer and parser //
diff --git a/src/json.hpp.re2c b/src/json.hpp.re2c
index 4dfab366..59b7e20d 100644
--- a/src/json.hpp.re2c
+++ b/src/json.hpp.re2c
@@ -172,14 +172,17 @@ class basic_json
     /// the type of an element const pointer
     using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer;
 
+    // forward declaration
+    template<typename Base> class json_reverse_iterator;
+
     /// an iterator for a basic_json container
     class iterator;
     /// a const iterator for a basic_json container
     class const_iterator;
     /// a reverse iterator for a basic_json container
-    class reverse_iterator;
+    using reverse_iterator = json_reverse_iterator<typename basic_json::iterator>;
     /// a const reverse iterator for a basic_json container
-    class const_reverse_iterator;
+    using const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>;
 
     /// @}
 
@@ -4863,522 +4866,6 @@ class basic_json
     };
 
   public:
-    /// a random access iterator for the basic_json class
-    class iterator : public std::iterator<std::random_access_iterator_tag, basic_json>
-    {
-        // allow basic_json class to access m_it
-        friend class basic_json;
-
-      public:
-        /// the type of the values when the iterator is dereferenced
-        using value_type = typename basic_json::value_type;
-        /// a type to represent differences between iterators
-        using difference_type = typename basic_json::difference_type;
-        /// defines a pointer to the type iterated over (value_type)
-        using pointer = typename basic_json::pointer;
-        /// defines a reference to the type iterated over (value_type)
-        using reference = typename basic_json::reference;
-        /// the category of the iterator
-        using iterator_category = std::bidirectional_iterator_tag;
-
-        /// default constructor
-        iterator() = default;
-
-        /// constructor for a given JSON instance
-        iterator(pointer object) : m_object(object)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = typename object_t::iterator();
-                    break;
-                }
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = typename array_t::iterator();
-                    break;
-                }
-                default:
-                {
-                    m_it.primitive_iterator = primitive_iterator_t();
-                    break;
-                }
-            }
-        }
-
-        /// copy constructor
-        iterator(const iterator& other) noexcept
-            : m_object(other.m_object), m_it(other.m_it)
-        {}
-
-        /// copy assignment
-        iterator& operator=(iterator other) noexcept (
-            std::is_nothrow_move_constructible<pointer>::value and
-            std::is_nothrow_move_assignable<pointer>::value and
-            std::is_nothrow_move_constructible<internal_iterator>::value and
-            std::is_nothrow_move_assignable<internal_iterator>::value
-        )
-        {
-            std::swap(m_object, other.m_object);
-            std::swap(m_it, other.m_it);
-            return *this;
-        }
-
-      private:
-        /// set the iterator to the first value
-        void set_begin()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = m_object->m_value.object->begin();
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = m_object->m_value.array->begin();
-                    break;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    // set to end so begin()==end() is true: null is empty
-                    m_it.primitive_iterator.set_end();
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator.set_begin();
-                    break;
-                }
-            }
-        }
-
-        /// set the iterator past the last value
-        void set_end()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator = m_object->m_value.object->end();
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator = m_object->m_value.array->end();
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator.set_end();
-                    break;
-                }
-            }
-        }
-
-      public:
-        /// return a reference to the value pointed to by the iterator
-        reference operator*()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return m_it.object_iterator->second;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return *m_it.array_iterator;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator.is_begin())
-                    {
-                        return *m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// dereference the iterator
-        pointer operator->()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return &(m_it.object_iterator->second);
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return &*m_it.array_iterator;
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator.is_begin())
-                    {
-                        return m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// post-increment (it++)
-        iterator operator++(int)
-        {
-            auto result = *this;
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator++;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator++;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator++;
-                    break;
-                }
-            }
-
-            return result;
-        }
-
-        /// pre-increment (++it)
-        iterator& operator++()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    ++m_it.object_iterator;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    ++m_it.array_iterator;
-                    break;
-                }
-
-                default:
-                {
-                    ++m_it.primitive_iterator;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// post-decrement (it--)
-        iterator operator--(int)
-        {
-            auto result = *this;
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    m_it.object_iterator--;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator--;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator--;
-                    break;
-                }
-            }
-
-            return result;
-        }
-
-        /// pre-decrement (--it)
-        iterator& operator--()
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    --m_it.object_iterator;
-                    break;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    --m_it.array_iterator;
-                    break;
-                }
-
-                default:
-                {
-                    --m_it.primitive_iterator;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// comparison: equal
-        bool operator==(const iterator& other) const
-        {
-            // if objects are not the same, the comparison is undefined
-            if (m_object != other.m_object)
-            {
-                throw std::domain_error("cannot compare iterators of different containers");
-            }
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return (m_it.object_iterator == other.m_it.object_iterator);
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return (m_it.array_iterator == other.m_it.array_iterator);
-                }
-
-                default:
-                {
-                    return (m_it.primitive_iterator == other.m_it.primitive_iterator);
-                }
-            }
-        }
-
-        /// comparison: not equal
-        bool operator!=(const iterator& other) const
-        {
-            return not operator==(other);
-        }
-
-        /// comparison: smaller
-        bool operator<(const iterator& other) const
-        {
-            // if objects are not the same, the comparison is undefined
-            if (m_object != other.m_object)
-            {
-                throw std::domain_error("cannot compare iterators of different containers");
-            }
-
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator< for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return (m_it.array_iterator < other.m_it.array_iterator);
-                }
-
-                default:
-                {
-                    return (m_it.primitive_iterator < other.m_it.primitive_iterator);
-                }
-            }
-        }
-
-        /// comparison: less than or equal
-        bool operator<=(const iterator& other) const
-        {
-            return not other.operator < (*this);
-        }
-
-        /// comparison: greater than
-        bool operator>(const iterator& other) const
-        {
-            return not operator<=(other);
-        }
-
-        /// comparison: greater than or equal
-        bool operator>=(const iterator& other) const
-        {
-            return not operator<(other);
-        }
-
-        /// add to iterator
-        iterator& operator+=(difference_type i)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator+= for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    m_it.array_iterator += i;
-                    break;
-                }
-
-                default:
-                {
-                    m_it.primitive_iterator += i;
-                    break;
-                }
-            }
-
-            return *this;
-        }
-
-        /// subtract from iterator
-        iterator& operator-=(difference_type i)
-        {
-            return operator+=(-i);
-        }
-
-        /// add to iterator
-        iterator operator+(difference_type i)
-        {
-            auto result = *this;
-            result += i;
-            return result;
-        }
-
-        /// subtract from iterator
-        iterator operator-(difference_type i)
-        {
-            auto result = *this;
-            result -= i;
-            return result;
-        }
-
-        /// return difference
-        difference_type operator-(const iterator& other) const
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator- for object iterators");
-                    return 0;
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return m_it.array_iterator - other.m_it.array_iterator;
-                }
-
-                default:
-                {
-                    return m_it.primitive_iterator - other.m_it.primitive_iterator;
-                }
-            }
-        }
-
-        /// access to successor
-        reference operator[](difference_type n)
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    throw std::domain_error("cannot use operator[] for object iterators");
-                }
-
-                case (basic_json::value_t::array):
-                {
-                    return *(m_it.array_iterator + n);
-                }
-
-                case (basic_json::value_t::null):
-                {
-                    throw std::out_of_range("cannot get value");
-                }
-
-                default:
-                {
-                    if (m_it.primitive_iterator == -n)
-                    {
-                        return *m_object;
-                    }
-                    else
-                    {
-                        throw std::out_of_range("cannot get value");
-                    }
-                }
-            }
-        }
-
-        /// return the key of an object iterator
-        typename object_t::key_type key() const
-        {
-            switch (m_object->m_type)
-            {
-                case (basic_json::value_t::object):
-                {
-                    return m_it.object_iterator->first;
-                }
-
-                default:
-                {
-                    throw std::domain_error("cannot use key() for non-object iterators");
-                }
-            }
-        }
-
-        /// return the key of an iterator
-        reference value()
-        {
-            return operator*();
-        }
-
-      private:
-        /// associated JSON instance
-        pointer m_object = nullptr;
-        /// the actual iterator of the associated instance
-        internal_iterator m_it = internal_iterator();
-    };
-
     /// a const random access iterator for the basic_json class
     class const_iterator : public std::iterator<std::random_access_iterator_tag, const basic_json>
     {
@@ -5874,70 +5361,96 @@ class basic_json
         internal_iterator m_it = internal_iterator();
     };
 
-    /*!
-    @brief a reverse random access iterator for the basic_json class
-
-    The reverse iterator is realized with the `std::reverse_iterator` adaptor.
-    This adaptor does not automatically inherit all functionality from the
-    base iterator class, so some functions need to be explicitly implemented
-    by either delegating them to the base class or by using the `base()`
-    function to access the underlying base iterator.
-
-    The following operators are implicitly inherited:
-
-    - `operator==`, `operator!=`, `operator<`, `operator<=`, `operator>`,
-      `operator>=`
-    - `operator-=`
-    - `operator->`, `operator*`
-    */
-    class reverse_iterator : public std::reverse_iterator<typename basic_json::iterator>
+    /// a random access iterator for the basic_json class
+    class iterator : public const_iterator
     {
       public:
-        /// shortcut to the reverse iterator adaptor
-        using base_iterator = std::reverse_iterator<typename basic_json::iterator>;
+        using base_iterator = const_iterator;
+        using pointer = typename basic_json::pointer;
+        using reference = typename basic_json::reference;
 
-        /// create reverse iterator from iterator
-        reverse_iterator(const typename base_iterator::iterator_type& it)
-            : base_iterator(it) {}
+        /// default constructor
+        iterator() = default;
 
-        /// create reverse iterator from base class
-        reverse_iterator(const base_iterator& it) : base_iterator(it) {}
+        /// constructor for a given JSON instance
+        iterator(pointer object) noexcept : base_iterator(object)
+        {}
+
+        /// copy constructor
+        iterator(const iterator& other) noexcept
+            : base_iterator(other)
+        {}
+
+        /// copy assignment
+        iterator& operator=(iterator other) noexcept(
+            std::is_nothrow_move_constructible<pointer>::value and
+            std::is_nothrow_move_assignable<pointer>::value and
+            std::is_nothrow_move_constructible<internal_iterator>::value and
+            std::is_nothrow_move_assignable<internal_iterator>::value
+        )
+        {
+            base_iterator::operator=(other);
+            return *this;
+        }
+
+        /// return a reference to the value pointed to by the iterator
+        reference operator*()
+        {
+            return const_cast<reference>(base_iterator::operator*());
+        }
+
+        /// dereference the iterator
+        pointer operator->()
+        {
+            return const_cast<pointer>(base_iterator::operator->());
+        }
 
         /// post-increment (it++)
-        reverse_iterator operator++(int)
+        iterator operator++(int)
         {
-            return base_iterator::operator++(1);
+            iterator result = *this;
+            base_iterator::operator++();
+            return result;
         }
 
         /// pre-increment (++it)
-        reverse_iterator& operator++()
+        iterator& operator++()
         {
             base_iterator::operator++();
             return *this;
         }
 
         /// post-decrement (it--)
-        reverse_iterator operator--(int)
+        iterator operator--(int)
         {
-            return base_iterator::operator--(1);
+            iterator result = *this;
+            base_iterator::operator--();
+            return result;
         }
 
         /// pre-decrement (--it)
-        reverse_iterator& operator--()
+        iterator& operator--()
         {
             base_iterator::operator--();
             return *this;
         }
 
         /// add to iterator
-        reverse_iterator& operator+=(difference_type i)
+        iterator& operator+=(difference_type i)
         {
             base_iterator::operator+=(i);
             return *this;
         }
 
+        /// subtract from iterator
+        iterator& operator-=(difference_type i)
+        {
+            base_iterator::operator-=(i);
+            return *this;
+        }
+
         /// add to iterator
-        reverse_iterator operator+(difference_type i) const
+        iterator operator+(difference_type i)
         {
             auto result = *this;
             result += i;
@@ -5945,7 +5458,90 @@ class basic_json
         }
 
         /// subtract from iterator
-        reverse_iterator operator-(difference_type i) const
+        iterator operator-(difference_type i)
+        {
+            auto result = *this;
+            result -= i;
+            return result;
+        }
+
+        difference_type operator-(const iterator& other) const
+        {
+            return base_iterator::operator-(other);
+        }
+
+        /// access to successor
+        reference operator[](difference_type n) const
+        {
+            return const_cast<reference>(base_iterator::operator[](n));
+        }
+
+        /// return the value of an iterator
+        reference value() const
+        {
+            return const_cast<reference>(base_iterator::value());
+        }
+    };
+
+    /// a template for a reverse iterator class
+    template<typename Base>
+    class json_reverse_iterator : public std::reverse_iterator<Base>
+    {
+      public:
+        /// shortcut to the reverse iterator adaptor
+        using base_iterator = std::reverse_iterator<Base>;
+        using reference = typename Base::reference;
+
+        /// create reverse iterator from iterator
+        json_reverse_iterator(const typename base_iterator::iterator_type& it)
+            : base_iterator(it) {}
+
+        /// create reverse iterator from base class
+        json_reverse_iterator(const base_iterator& it) : base_iterator(it) {}
+
+        /// post-increment (it++)
+        json_reverse_iterator operator++(int)
+        {
+            return base_iterator::operator++(1);
+        }
+
+        /// pre-increment (++it)
+        json_reverse_iterator& operator++()
+        {
+            base_iterator::operator++();
+            return *this;
+        }
+
+        /// post-decrement (it--)
+        json_reverse_iterator operator--(int)
+        {
+            return base_iterator::operator--(1);
+        }
+
+        /// pre-decrement (--it)
+        json_reverse_iterator& operator--()
+        {
+            base_iterator::operator--();
+            return *this;
+        }
+
+        /// add to iterator
+        json_reverse_iterator& operator+=(difference_type i)
+        {
+            base_iterator::operator+=(i);
+            return *this;
+        }
+
+        /// add to iterator
+        json_reverse_iterator operator+(difference_type i) const
+        {
+            auto result = *this;
+            result += i;
+            return result;
+        }
+
+        /// subtract from iterator
+        json_reverse_iterator operator-(difference_type i) const
         {
             auto result = *this;
             result -= i;
@@ -5953,7 +5549,7 @@ class basic_json
         }
 
         /// return difference
-        difference_type operator-(const reverse_iterator& other) const
+        difference_type operator-(const json_reverse_iterator& other) const
         {
             return this->base() - other.base();
         }
@@ -5979,97 +5575,6 @@ class basic_json
         }
     };
 
-    /// a const reverse random access iterator for the basic_json class
-    class const_reverse_iterator : public std::reverse_iterator<typename basic_json::const_iterator>
-    {
-      public:
-        /// shortcut to the reverse iterator adaptor
-        using base_iterator = std::reverse_iterator<typename basic_json::const_iterator>;
-
-        /// create reverse iterator from iterator
-        const_reverse_iterator(const typename base_iterator::iterator_type& it)
-            : base_iterator(it) {}
-
-        /// create reverse iterator from base class
-        const_reverse_iterator(const base_iterator& it) : base_iterator(it) {}
-
-        /// post-increment (it++)
-        const_reverse_iterator operator++(int)
-        {
-            return base_iterator::operator++(1);
-        }
-
-        /// pre-increment (++it)
-        const_reverse_iterator& operator++()
-        {
-            base_iterator::operator++();
-            return *this;
-        }
-
-        /// post-decrement (it--)
-        const_reverse_iterator operator--(int)
-        {
-            return base_iterator::operator--(1);
-        }
-
-        /// pre-decrement (--it)
-        const_reverse_iterator& operator--()
-        {
-            base_iterator::operator--();
-            return *this;
-        }
-
-        /// add to iterator
-        const_reverse_iterator& operator+=(difference_type i)
-        {
-            base_iterator::operator+=(i);
-            return *this;
-        }
-
-        /// add to iterator
-        const_reverse_iterator operator+(difference_type i) const
-        {
-            auto result = *this;
-            result += i;
-            return result;
-        }
-
-        /// subtract from iterator
-        const_reverse_iterator operator-(difference_type i) const
-        {
-            auto result = *this;
-            result -= i;
-            return result;
-        }
-
-        /// return difference
-        difference_type operator-(const const_reverse_iterator& other) const
-        {
-            return this->base() - other.base();
-        }
-
-        /// access to successor
-        const_reference operator[](difference_type n) const
-        {
-            return *(this->operator+(n));
-        }
-
-        /// return the key of an object iterator
-        typename object_t::key_type key() const
-        {
-            auto it = --this->base();
-            return it.key();
-        }
-
-        /// return the value of an iterator
-        const_reference value() const
-        {
-            auto it = --this->base();
-            return it.operator * ();
-        }
-    };
-
-
   private:
     //////////////////////
     // lexer and parser //