diff --git a/CMakeLists.txt b/CMakeLists.txt
index abb619a..9b12114 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
-set(BLT_VERSION 0.21.0)
+set(BLT_VERSION 0.21.1)
 set(BLT_TEST_VERSION 0.0.1)
 
 set(BLT_TARGET BLT)
diff --git a/include/blt/std/iterator.h b/include/blt/std/iterator.h
index 4d70916..933bf38 100644
--- a/include/blt/std/iterator.h
+++ b/include/blt/std/iterator.h
@@ -28,6 +28,7 @@
 namespace blt
 {
     
+    // forward declare useful types
     template<typename Iter, typename = std::void_t<>>
     class enumerator;
     
@@ -39,6 +40,7 @@ namespace blt
         template<typename Iter, typename = std::void_t<>>
         class enumerate_wrapper;
         
+        // struct which is returned by the enumerator
         template<typename T>
         struct enumerate_item
         {
@@ -46,6 +48,38 @@ namespace blt
             T value;
         };
         
+        template<typename Iter1, typename Iter2>
+        class pair_iterator_base
+        {
+            public:
+                explicit pair_iterator_base(Iter1 iter1, Iter2 iter2): m_iter1(std::move(iter1)), m_iter2(std::move(iter2))
+                {}
+                
+                friend bool operator==(const pair_iterator_base& a, const pair_iterator_base& b)
+                {
+                    return a.m_iter1 == b.m_iter1;
+                }
+                
+                friend bool operator!=(const pair_iterator_base& a, const pair_iterator_base& b)
+                {
+                    return a.m_iter1 != b.m_iter1;
+                }
+                
+                auto iter1() const
+                {
+                    return m_iter1;
+                }
+                
+                auto iter2() const
+                {
+                    return m_iter2;
+                }
+                
+            protected:
+                Iter1 m_iter1;
+                Iter2 m_iter2;
+        };
+        
         template<typename Iter>
         class enumerate_iterator_base
         {
@@ -198,9 +232,24 @@ namespace blt
                 
                 auto rev() const
                 {
-                    return enumerator_rev<Iter>{this->end_.base(), this->begin_.base(), this->container_size, this->begin_.get_index(),
+                    return enumerator_rev<Iter>{this->end_.base(),
+                                                this->begin_.base(),
+                                                this->end_.get_index(),
+                                                this->begin_.get_index(),
                                                 this->container_size};
                 }
+                
+                auto skip(blt::size_t offset)
+                {
+                    auto begin = this->begin();
+                    for (blt::size_t i = 0; i < offset; i++)
+                        ++begin;
+                    return enumerator<Iter>{begin.base(),
+                                            this->end_.base(),
+                                            begin.get_index(),
+                                            this->end_.get_index(),
+                                            this->container_size};
+                }
             
             protected:
                 blt::size_t container_size;
@@ -214,8 +263,23 @@ namespace blt
                 
                 auto rev() const
                 {
-                    return enumerator<Iter>{this->end_.base().base(), this->begin_.base().base(), this->end_.base().get_index(),
-                                            this->begin_.base().get_index(), this->container_size};
+                    return enumerator<Iter>{this->end_.base().base(),
+                                            this->begin_.base().base(),
+                                            this->end_.base().get_index(),
+                                            this->begin_.base().get_index(),
+                                            this->container_size};
+                }
+                
+                auto skip(blt::size_t offset)
+                {
+                    auto begin = this->begin();
+                    for (blt::size_t i = 0; i < offset; i++)
+                        --begin;
+                    return enumerator<Iter>{begin.base(),
+                                            this->end_.base(),
+                                            begin.get_index(),
+                                            this->end_.get_index(),
+                                            this->container_size};
                 }
         };
     }
@@ -234,11 +298,6 @@ namespace blt
     {
         public:
             using iterator::enumerator_reversible<Iter, iterator::enumerate_wrapper<Iter>>::enumerator_reversible;
-            
-            auto skip(blt::size_t offset)
-            {
-            
-            }
     };
     
     template<typename Iter>