wow working iterators!

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
-set(BLT_VERSION 1.1.7)
+set(BLT_VERSION 1.1.8)
 
 set(BLT_TARGET BLT)
 

include/blt/iterator/common.h

@@ -21,7 +21,10 @@
 
 #include <type_traits>
 #include <iterator>
+#include <blt/std/types.h>
+#include <blt/iterator/fwddecl.h>
 #include <blt/meta/meta.h>
+#include <blt/meta/iterator.h>
 
 namespace blt::iterator
 {
@@ -37,10 +40,7 @@ namespace blt::iterator
         
         base_wrapper operator--(int)
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::bidirectional_iterator_tag> ||
-                          std::is_same_v<typename Derived::iterator_category,
-                                  std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_bidirectional_or_better_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             auto tmp = *this;
             --*this;
             return tmp;
@@ -48,8 +48,7 @@ namespace blt::iterator
         
         auto operator[](blt::ptrdiff_t n) const
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_random_access_iterator_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             return *(*this + n);
         }
         
@@ -60,29 +59,25 @@ namespace blt::iterator
         
         friend bool operator<(const base_wrapper& a, const base_wrapper& b)
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_random_access_iterator_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             return b - a > 0;
         }
         
         friend bool operator>(const base_wrapper& a, const base_wrapper& b)
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_random_access_iterator_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             return b < a;
         }
         
         friend bool operator>=(const base_wrapper& a, base_wrapper& b)
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_random_access_iterator_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             return !(a < b); // NOLINT
         }
         
         friend bool operator<=(const base_wrapper& a, const base_wrapper& b)
         {
-            static_assert(std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>,
-                          "Iterator must allow random access");
+            static_assert(meta::is_random_access_iterator_category_v<typename Derived::iterator_category>, "Iterator must allow random access");
             return !(a > b); // NOLINT
         }
         
@@ -127,6 +122,28 @@ namespace blt::iterator
         {
             return *this->iter;
         }
+
+//        zip_wrapper& operator++()
+//        {
+//            return *this;
+//        }
+//
+//        zip_wrapper& operator--()
+//        {
+//            return *this;
+//        }
+//
+//        friend zip_wrapper operator+(const zip_wrapper& a, blt::ptrdiff_t n)
+//        {
+//            static_assert(std::is_same_v<iterator_category, std::random_access_iterator_tag>,
+//                          "Iterator must allow random access");
+//        }
+//
+//        friend zip_wrapper operator-(const zip_wrapper& a, blt::ptrdiff_t n)
+//        {
+//            static_assert(std::is_same_v<iterator_category, std::random_access_iterator_tag>,
+//                          "Iterator must allow random access");
+//        }
     };
     
     namespace impl
@@ -142,8 +159,17 @@ namespace blt::iterator
                     auto begin = d->begin();
                     auto end = d->end();
                     
-                    if constexpr (std::is_same_v<typename Derived::iterator_category, std::forward_iterator_tag> ||
-                                  std::is_same_v<typename Derived::iterator_category, std::bidirectional_iterator_tag>)
+                    if constexpr (meta::is_random_access_iterator_category_v<typename Derived::iterator_category>)
+                    {
+                        // random access iterators can have math directly applied to them.
+                        if constexpr (check)
+                        {
+                            return Derived{begin + std::min(static_cast<blt::ptrdiff_t>(n), std::distance(begin, end)), end};
+                        } else
+                        {
+                            return Derived{begin + n, end};
+                        }
+                    } else
                     {
                         for (blt::size_t i = 0; i < n; i++)
                         {
@@ -155,16 +181,6 @@ namespace blt::iterator
                             ++begin;
                         }
                         return Derived{std::move(begin), std::move(end)};
-                    } else if constexpr (std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>)
-                    {
-                        // random access iterators can have math directly applied to them.
-                        if constexpr (check)
-                        {
-                            return Derived{begin + std::min(static_cast<blt::ptrdiff_t>(n), std::distance(begin, end)), end};
-                        } else
-                        {
-                            return Derived{begin + n, end};
-                        }
                     }
                 }
             
@@ -183,15 +199,15 @@ namespace blt::iterator
                 template<bool check>
                 auto take_base(blt::size_t n)
                 {
-                    static_assert(!std::is_same_v<typename Derived::iterator_category, std::input_iterator_tag>,
+                    static_assert(!meta::is_input_iterator_category_v<typename Derived::iterator_category>,
                                   "Cannot .take() on an input iterator!");
                     auto* d = static_cast<Derived*>(this);
                     auto begin = d->begin();
                     auto end = d->end();
                     
                     // take variant for forward and bidirectional iterators
-                    if constexpr (std::is_same_v<typename Derived::iterator_category, std::forward_iterator_tag> ||
-                                  std::is_same_v<typename Derived::iterator_category, std::bidirectional_iterator_tag>)
+                    if constexpr (meta::is_forward_iterator_category_v<typename Derived::iterator_category> ||
+                                  meta::is_bidirectional_iterator_category_v<typename Derived::iterator_category>)
                     {
                         // with these guys we have to loop forward to move the iterators. an unfortunate inefficiency
                         auto new_end = begin;
@@ -205,7 +221,7 @@ namespace blt::iterator
                             ++new_end;
                         }
                         return Derived{std::move(begin), std::move(new_end)};
-                    } else if constexpr (std::is_same_v<typename Derived::iterator_category, std::random_access_iterator_tag>)
+                    } else if constexpr (meta::is_random_access_iterator_category_v<typename Derived::iterator_category>)
                     {
                         // random access iterators can have math directly applied to them.
                         if constexpr (check)
@@ -232,7 +248,7 @@ namespace blt::iterator
                                public impl::skip_t<iterator_container<IterBase>>
     {
         public:
-            using iterator_category = typename IterBase::iterator_category;
+            using iterator_category = typename std::iterator_traits<IterBase>::iterator_category;
             using iterator = IterBase;
             
             iterator_container(IterBase begin, IterBase end): m_begin(std::move(begin)), m_end(std::move(end))
@@ -242,15 +258,39 @@ namespace blt::iterator
             iterator_container(Iter&& begin, Iter&& end): m_begin(std::forward<Iter>(begin)), m_end(std::forward<Iter>(end))
             {}
             
-            auto rev()
+            auto rev() const
             {
-                static_assert((std::is_same_v<typename IterBase::iterator_category, std::bidirectional_iterator_tag> ||
-                               std::is_same_v<typename IterBase::iterator_category, std::random_access_iterator_tag>),
+                static_assert(meta::is_bidirectional_or_better_category_v<iterator_category>,
                               ".rev() must be used with bidirectional (or better) iterators!");
                 return iterator_container<std::reverse_iterator<IterBase>>{std::reverse_iterator<IterBase>{end()},
                                                                            std::reverse_iterator<IterBase>{begin()}};
             }
             
+            template<typename... Iter>
+            auto zip(iterator_pair<Iter>... iterator_pairs) const
+            {
+                return zip_iterator_container(iterator_pair<decltype(begin())>{begin(), end()}, iterator_pairs...);
+            }
+            
+            template<typename... Container>
+            auto zip(Container& ... containers) const
+            {
+                return zip_iterator_container(iterator_pair<decltype(begin())>{begin(), end()},
+                                              iterator_pair{containers.begin(), containers.end()}...);
+            }
+            
+            template<typename... Container>
+            auto zip(const Container& ... containers) const
+            {
+                return zip_iterator_container(iterator_pair<decltype(begin())>{begin(), end()},
+                                              iterator_pair{containers.begin(), containers.end()}...);
+            }
+            
+            auto enumerate() const
+            {
+                return enumerate_iterator_container{begin(), end(), static_cast<blt::size_t>(std::distance(begin(), end()))};
+            }
+            
             auto begin() const
             {
                 return m_begin;

include/blt/iterator/enumerate.h

@@ -20,7 +20,6 @@
 #define BLT_ITERATOR_ENUMERATE_H
 
 #include <blt/iterator/common.h>
-#include <blt/meta/meta.h>
 #include <tuple>
 
 namespace blt
@@ -43,17 +42,110 @@ namespace blt
         class enumerate_wrapper : public passthrough_wrapper<Iter, enumerate_wrapper<Iter>>
         {
             public:
-                using passthrough_wrapper<Iter, enumerate_wrapper<Iter>>::passthrough_wrapper;
+                enumerate_wrapper(blt::size_t index, Iter iter): passthrough_wrapper<Iter, enumerate_wrapper<Iter>>(std::move(iter)), index(index)
+                {}
+                
+                using iterator_category = typename std::iterator_traits<Iter>::iterator_category;
+                using value_type = enumerate_item<meta::deref_return_t<Iter>>;
+                using difference_type = blt::ptrdiff_t;
+                using pointer = value_type;
+                using reference = value_type;
                 
                 enumerate_item<meta::deref_return_t<Iter>> operator*() const
                 {
-                    return *this->iter;
+                    return {index, *this->iter};
                 }
+                
+                enumerate_wrapper& operator++()
+                {
+                    ++index;
+                    ++this->iter;
+                    return *this;
+                }
+                
+                enumerate_wrapper& operator--()
+                {
+                    --index;
+                    --this->iter;
+                    return *this;
+                }
+                
+                friend enumerate_wrapper operator+(const enumerate_wrapper& a, blt::ptrdiff_t n)
+                {
+                    static_assert(meta::is_random_access_iterator_v<Iter>, "Iterator must allow random access");
+                    auto copy = a;
+                    copy.index += n;
+                    copy.iter = copy.iter + n;
+                    return copy;
+                }
+                
+                friend enumerate_wrapper operator-(const enumerate_wrapper& a, blt::ptrdiff_t n)
+                {
+                    static_assert(meta::is_random_access_iterator_v<Iter>, "Iterator must allow random access");
+                    auto copy = a;
+                    copy.index -= n;
+                    copy.iter = copy.iter - n;
+                    return copy;
+                }
+            
             private:
                 blt::size_t index;
         };
     }
     
+    template<typename Iter>
+    class enumerate_iterator_container : public iterator::iterator_container<iterator::enumerate_wrapper<Iter>>
+    {
+        public:
+            using iterator::iterator_container<iterator::enumerate_wrapper<Iter>>::iterator_container;
+            
+            enumerate_iterator_container(Iter begin, Iter end, blt::size_t size):
+                    iterator::iterator_container<iterator::enumerate_wrapper<Iter>>(
+                            iterator::enumerate_wrapper<Iter>{0, std::move(begin)}, iterator::enumerate_wrapper<Iter>{size, std::move(end)})
+            {}
+    };
+    
+    template<typename Iter>
+    enumerate_iterator_container(Iter, Iter, blt::size_t) -> enumerate_iterator_container<Iter>;
+    
+    namespace iterator::impl
+    {
+        template<typename Derived>
+        class enumerate_t
+        {
+            public:
+                auto enumerate()
+                {
+                    auto* d = static_cast<Derived*>(this);
+                    return enumerate_iterator_container{d->begin(), d->end(), static_cast<blt::size_t>(std::distance(d->begin(), d->end()))};
+                }
+        };
+    }
+    
+    template<typename T>
+    static inline auto enumerate(T& container)
+    {
+        return enumerate_iterator_container{container.begin(), container.end(), container.size()};
+    }
+    
+    template<typename T>
+    static inline auto enumerate(const T& container)
+    {
+        return enumerate_iterator_container{container.begin(), container.end(), container.size()};
+    }
+    
+    template<typename T, blt::size_t size>
+    static inline auto enumerate(const T(& container)[size])
+    {
+        return enumerate_iterator_container{&container[0], &container[size], size};
+    }
+    
+    template<typename T, blt::size_t size>
+    static inline auto enumerate(T(& container)[size])
+    {
+        return enumerate_iterator_container{&container[0], &container[size], size};
+    }
+    
 }
 
 #endif //BLT_ITERATOR_ENUMERATE_H

include/blt/iterator/fwddecl.h

@@ -0,0 +1,61 @@
+#pragma once
+/*
+ *  Copyright (C) 2024  Brett Terpstra
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef BLT_ITERATOR_FWDDECL_H
+#define BLT_ITERATOR_FWDDECL_H
+
+namespace blt
+{
+    template<typename... Iter>
+    class zip_iterator_container;
+    
+    template<typename Iter>
+    class enumerate_iterator_container;
+    
+    namespace iterator
+    {
+        template<typename Iter>
+        struct iterator_pair;
+        
+        template<typename T>
+        struct enumerate_item;
+        
+        template<typename Iter>
+        class enumerate_wrapper;
+        
+        template<typename... Iter>
+        struct zip_wrapper;
+        
+        namespace impl
+        {
+            template<typename Derived>
+            class skip_t;
+            
+            template<typename Derived>
+            class take_t;
+            
+            template<typename Derived>
+            class zip_t;
+            
+            template<typename Derived>
+            class enumerate_t;
+        }
+    }
+}
+
+#endif //BLT_ITERATOR_FWDDECL_H

include/blt/iterator/iterator.h

@@ -19,12 +19,9 @@
 #ifndef BLT_ITERATOR_H
 #define BLT_ITERATOR_H
 
-#include <blt/std/types.h>
-#include <blt/std/logging.h>
 #include <blt/iterator/common.h>
 #include <blt/iterator/zip.h>
-#include <blt/meta/meta.h>
-#include <blt/meta/iterator.h>
+#include <blt/iterator/enumerate.h>
 #include <type_traits>
 #include <iterator>
 #include <tuple>
@@ -32,723 +29,30 @@
 namespace blt
 {
     
-    // forward declare useful types
-    template<typename Iter, typename = std::void_t<>>
-    class enumerator;
-    
-    template<typename Iter, typename = std::void_t<>>
-    class enumerator_rev;
-    
-    template<typename Iter1, typename Iter2, typename = std::void_t<>>
-    class pair_iterator;
-    
-    template<typename Iter, typename Iter2, typename = std::void_t<>>
-    class pair_iterator_rev;
-    
-    template<typename... Iter>
-    class zip_iterator;
-    
-    template<typename... Iter>
-    class zip_iterator_rev;
-    
-    namespace iterator
+    template<typename T>
+    static inline auto iterate(T& container)
     {
-        template<typename Iter, typename = std::void_t<>>
-        class enumerate_wrapper;
-        
-        template<typename Iter1, typename Iter2, typename = std::void_t<>>
-        class pair_wrapper;
-        
-        /**
-         * struct which is returned by the enumerator.
-         * @tparam T type to store.
-         */
-        template<typename T>
-        struct enumerate_item
-        {
-            blt::size_t index;
-            T value;
-        };
-        
-        /**
-         * base class for iterators which operate on pairs of values. Handles comparison.
-         * @tparam Iter1 first iterator type. this will be used for comparison.
-         * @tparam Iter2 second iterator type. this value is not modified by this class.
-         */
-        template<typename Iter1, typename Iter2>
-        class dual_iterator_base
-        {
-            public:
-                explicit dual_iterator_base(Iter1 iter1, Iter2 iter2): m_iter1(std::move(iter1)), m_iter2(std::move(iter2))
-                {}
-                
-                friend bool operator==(const dual_iterator_base& a, const dual_iterator_base& b)
-                {
-                    return a.m_iter1 == b.m_iter1;
-                }
-                
-                friend bool operator!=(const dual_iterator_base& a, const dual_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;
-        };
-        
-        /**
-         * Base class for all enumerator iterators. Handles the deference (*) operator.
-         * @tparam Iter iterator type
-         */
-        template<typename Iter>
-        class enumerate_iterator_base : public dual_iterator_base<Iter, blt::size_t>
-        {
-            public:
-                explicit enumerate_iterator_base(Iter iter, blt::size_t place = 0):
-                        dual_iterator_base<Iter, blt::size_t>(std::move(iter), place)
-                {}
-                
-                enumerate_item<blt::meta::deref_return_t<Iter>> operator*() const
-                {
-                    return {this->m_iter2, *this->m_iter1};
-                }
-        };
-        
-        template<typename Iter1, typename Iter2>
-        class pair_iterator_base : public dual_iterator_base<Iter1, Iter2>
-        {
-            public:
-                using dual_iterator_base<Iter1, Iter2>::dual_iterator_base;
-                
-                std::pair<blt::meta::deref_return_t<Iter1>, blt::meta::deref_return_t<Iter2>> operator*() const
-                {
-                    return {*this->m_iter1, *this->m_iter2};
-                }
-        };
-        
-        /**
-         * Forward iterator base class. Contains the ++ operator.
-         * @tparam Base iterator base type.
-         */
-        template<typename Base>
-        class forward_iterator_base : public Base
-        {
-            public:
-                using Base::Base;
-                
-                forward_iterator_base& operator++()
-                {
-                    ++this->m_iter1;
-                    ++this->m_iter2;
-                    return *this;
-                }
-                
-                forward_iterator_base operator++(int)
-                {
-                    auto tmp = *this;
-                    ++*this;
-                    return tmp;
-                }
-        };
-        
-        /**
-         * Bidirectional iterator base class. Contains the -- operator.
-         * @tparam Base iterator base type.
-         */
-        template<typename Base>
-        class bidirectional_iterator_base : public Base
-        {
-            public:
-                using Base::Base;
-                
-                bidirectional_iterator_base& operator--()
-                {
-                    --this->m_iter1;
-                    --this->m_iter2;
-                    return *this;
-                }
-                
-                bidirectional_iterator_base operator--(int)
-                {
-                    auto tmp = *this;
-                    --*this;
-                    return tmp;
-                }
-        };
-        
-        template<typename Iter>
-        using enumerate_forward_iterator = forward_iterator_base<enumerate_iterator_base<Iter>>;
-        
-        template<typename Iter>
-        using enumerate_bidirectional_iterator = bidirectional_iterator_base<enumerate_forward_iterator<Iter>>;
-        
-        template<typename Iter1, typename Iter2>
-        using pair_forward_iterator = forward_iterator_base<pair_iterator_base<Iter1, Iter2>>;
-        
-        template<typename Iter1, typename Iter2>
-        using pair_bidirectional_iterator = bidirectional_iterator_base<pair_forward_iterator<Iter1, Iter2>>;
-        
-        /**
-         * Enumerator wrapper class specialization for forward iterators.
-         * @tparam Iter iterator type
-         */
-        template<typename Iter>
-        class enumerate_wrapper<Iter, std::enable_if_t<blt::meta::is_forward_iterator_v<Iter>, std::void_t<std::forward_iterator_tag>>>
-                : public enumerate_forward_iterator<Iter>
-        {
-            public:
-                using iterator_category = std::forward_iterator_tag;
-                using value_type = enumerate_item<blt::meta::deref_return_t<Iter>>;
-                using difference_type = typename std::iterator_traits<Iter>::difference_type;
-                using pointer = value_type;
-                using reference = value_type;
-                
-                using enumerate_forward_iterator<Iter>::enumerate_forward_iterator;
-        };
-        
-        /**
-         * Pair wrapper class specialization for forward iterators.
-         * @tparam Iter iterator type
-         */
-        template<typename Iter1, typename Iter2>
-        class pair_wrapper<Iter1, Iter2, std::enable_if_t<
-                blt::meta::is_forward_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                std::void_t<std::forward_iterator_tag>>> : public pair_forward_iterator<Iter1, Iter2>
-        {
-            public:
-                using iterator_category = std::forward_iterator_tag;
-                using value_type = std::pair<blt::meta::deref_return_t<Iter1>, blt::meta::deref_return_t<Iter2>>;
-                using difference_type = std::common_type_t<typename std::iterator_traits<Iter1>::difference_type, typename std::iterator_traits<Iter2>::difference_type>;
-                using pointer = value_type;
-                using reference = value_type;
-                
-                using pair_forward_iterator<Iter1, Iter2>::pair_forward_iterator;
-        };
-        
-        /**
-         * Enumerator wrapper class for bidirectional iterators or random access iterators.
-         * @tparam Iter iterator type.
-         */
-        template<typename Iter>
-        class enumerate_wrapper<Iter, std::enable_if_t<blt::meta::is_bidirectional_or_better_v<Iter>, std::void_t<std::bidirectional_iterator_tag>>>
-                : public enumerate_bidirectional_iterator<Iter>
-        {
-            public:
-                using iterator_category = std::bidirectional_iterator_tag;
-                using value_type = enumerate_item<blt::meta::deref_return_t<Iter>>;
-                using difference_type = typename std::iterator_traits<Iter>::difference_type;
-                using pointer = value_type;
-                using reference = value_type;
-                
-                using enumerate_bidirectional_iterator<Iter>::enumerate_bidirectional_iterator;
-        };
-        
-        /**
-         * Pair wrapper class for bidirectional iterators or random access iterators.
-         * @tparam Iter iterator type.
-         */
-        template<typename Iter1, typename Iter2>
-        class pair_wrapper<Iter1, Iter2, std::enable_if_t<
-                blt::meta::is_bidirectional_or_better_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                std::void_t<std::bidirectional_iterator_tag>>> : public pair_bidirectional_iterator<Iter1, Iter2>
-        {
-            public:
-                using iterator_category = std::bidirectional_iterator_tag;
-                using value_type = std::pair<blt::meta::deref_return_t<Iter1>, blt::meta::deref_return_t<Iter2>>;
-                using difference_type = std::common_type_t<typename std::iterator_traits<Iter1>::difference_type, typename std::iterator_traits<Iter2>::difference_type>;
-                using pointer = value_type;
-                using reference = value_type;
-                
-                using pair_bidirectional_iterator<Iter1, Iter2>::pair_bidirectional_iterator;
-        };
-        
-        /**
-         * Base class for storing begin/end iterators.
-         * @tparam IterWrapper wrapper used to iterate
-         * @tparam CompleteClass completed class returned from skip/take methods
-         */
-        template<typename IterWrapper, typename CompleteClass>
-        class iterator_storage_base
-        {
-            public:
-                explicit iterator_storage_base(IterWrapper begin, IterWrapper end): begin_(std::move(begin)), end_(std::move(end))
-                {}
-                
-                auto begin()
-                {
-                    return begin_;
-                }
-                
-                auto end()
-                {
-                    return end_;
-                }
-                
-                /**
-                 * Creates an enumerator that skips the first n elements.
-                 * @param amount amount of values to skip.
-                 */
-                auto skip(blt::size_t amount)
-                {
-                    auto begin = this->begin_;
-                    for (blt::size_t i = 0; i < amount; i++)
-                        ++begin;
-                    return CompleteClass{begin.iter1(),
-                                         this->end_.iter1(),
-                                         begin.iter2(),
-                                         this->end_.iter2()};
-                }
-                
-                /**
-                 * Creates an enumerator that yields the first n elements, or UB if the underlying iterator ends sooner.
-                 * @param amount amount to take.
-                 */
-                auto take(blt::size_t amount)
-                {
-                    auto end = this->begin();
-                    for (blt::size_t i = 0; i < amount; i++)
-                        ++end;
-                    return CompleteClass{this->begin_.iter1(),
-                                         end.iter1(),
-                                         this->begin_.iter2(),
-                                         end.iter2()};
-                }
-            
-            protected:
-                IterWrapper begin_;
-                IterWrapper end_;
-        };
-        
-        /**
-         * Reversible (bidirectional) base class storing the begin / end iterators.
-         * @tparam Iter iterator type.
-         * @tparam IterWrapper wrapper used to iterate.
-         * @tparam CompleteClass completed class returned from skip/take methods
-         * @tparam CompleteClassRev reverse version of CompleteClass, returned from rev
-         */
-        template<typename IterWrapper, typename CompleteClass, typename CompleteClassRev>
-        class iterator_storage_reversible : public iterator_storage_base<IterWrapper, CompleteClass>
-        {
-            public:
-                explicit iterator_storage_reversible(IterWrapper begin, IterWrapper end):
-                        iterator_storage_base<IterWrapper, CompleteClass>{std::move(begin), std::move(end)}
-                {}
-                
-                /**
-                 * Reverses the enumerator’s direction.
-                 */
-                auto rev() const
-                {
-                    return CompleteClassRev{this->end_.iter1(),
-                                            this->begin_.iter1(),
-                                            this->end_.iter2(),
-                                            this->begin_.iter2()};
-                }
-        };
-        
-        /**
-         * Random access base class storage for begin/end iterators.
-         * Has updated skip and take methods which make use of the random access nature of the iterator.
-         * @tparam Iter iterator type.
-         * @tparam IterWrapper wrapper used to iterate.
-         * @tparam CompleteClass completed class returned from skip/take methods
-         * @tparam CompleteClassRev reverse version of CompleteClass, returned from rev
-         */
-        template<typename IterWrapper, typename CompleteClass, typename CompleteClassRev>
-        class iterator_storage_random_access : public iterator_storage_reversible<IterWrapper, CompleteClass, CompleteClassRev>
-        {
-            public:
-                using iterator_storage_reversible<IterWrapper, CompleteClass, CompleteClassRev>::iterator_storage_reversible;
-                
-                auto skip(blt::size_t amount)
-                {
-                    return CompleteClass{this->begin_.iter1() + amount,
-                                         this->end_.iter1(),
-                                         this->begin_.iter2() + amount,
-                                         this->end_.iter2()};
-                }
-                
-                auto take(blt::size_t amount)
-                {
-                    return CompleteClass{this->begin_.iter1(),
-                                         this->begin_.iter1() + amount,
-                                         this->begin_.iter2(),
-                                         this->begin_.iter2() + amount};
-                }
-        };
-        
-        /**
-         * Reversible (bidirectional) base class for storing the begin/end iterators, operates in reverse for reverse iteration.
-         * @tparam Iter iterator type.
-         * @tparam IterWrapper wrapper used to iterate (std::reverse_iterator<enumerate_wrapper>).
-         * @tparam CompleteClass completed class returned from skip/take methods
-         * @tparam CompleteClassRev reverse version of CompleteClass, returned from rev
-         */
-        template<typename IterWrapper, typename CompleteClass, typename CompleteClassRev>
-        class iterator_storage_reversible_rev : public iterator_storage_reversible<IterWrapper, CompleteClass, CompleteClassRev>
-        {
-            public:
-                using iterator_storage_reversible<IterWrapper, CompleteClass, CompleteClassRev>::iterator_storage_reversible;
-                
-                auto rev() const
-                {
-                    return CompleteClass{this->end_.base().iter1(),
-                                         this->begin_.base().iter1(),
-                                         this->end_.base().iter2(),
-                                         this->begin_.base().iter2()};
-                }
-                
-                auto skip(blt::size_t amount)
-                {
-                    auto begin = this->begin_.base();
-                    for (blt::size_t i = 0; i < amount; i++)
-                        --begin;
-                    return CompleteClassRev{begin.iter1(),
-                                            this->end_.base().iter1(),
-                                            begin.iter2(),
-                                            this->end_.base().iter2()};
-                }
-                
-                auto take(blt::size_t amount)
-                {
-                    auto end = this->begin_.base();
-                    for (blt::size_t i = 0; i < amount; i++)
-                        --end;
-                    return CompleteClassRev{
-                            this->begin_.base().iter1(),
-                            end.iter1(),
-                            this->begin_.base().iter2(),
-                            end.iter2()};
-                }
-        };
-        
-        /**
-         * Random access base class for storing the begin/end iterator.
-         * Has updated skip and take methods which make use of the random access nature of the iterator.
-         * Operates in reverse for reverse iteration.
-         * @tparam Iter iterator type.
-         * @tparam IterWrapper wrapper used to iterate (std::reverse_iterator<enumerate_wrapper>).
-         * @tparam CompleteClass completed class returned from skip/take methods
-         * @tparam CompleteClassRev reverse version of CompleteClass, returned from rev
-         */
-        template<typename IterWrapper, typename CompleteClass, typename CompleteClassRev>
-        class iterator_storage_random_access_rev : public iterator_storage_reversible_rev<IterWrapper, CompleteClass, CompleteClassRev>
-        {
-            public:
-                using iterator_storage_reversible_rev<IterWrapper, CompleteClass, CompleteClassRev>::iterator_storage_reversible_rev;
-                
-                auto skip(blt::size_t amount)
-                {
-                    return CompleteClassRev{this->begin_.base().iter1() - amount,
-                                            this->end_.base().iter1(),
-                                            this->begin_.base().iter2() - amount,
-                                            this->end_.base().iter2()};
-                }
-                
-                auto take(blt::size_t amount)
-                {
-                    return CompleteClassRev{this->begin_.base().iter1(),
-                                            this->begin_.base().iter1() - amount,
-                                            this->begin_.base().iter2(),
-                                            this->begin_.base().iter2() - amount};
-                }
-        };
-        
-        /**
-         * Base class for types which can be converted to an enumerator
-         */
-        template<typename Derived, typename CompleteEnumerator>
-        class enumerator_convertible
-        {
-            public:
-                auto enumerate()
-                {
-                    auto* b = static_cast<Derived*>(this);
-                    return CompleteEnumerator{b->begin(), b->end(), static_cast<blt::size_t>(std::distance(b->begin(), b->end()))};
-                }
-        };
+        return iterator::iterator_container<decltype(container.begin())>{container.begin(), container.end()};
     }
     
-    /**
-     * Enumerator specialization for forward iterators
-     */
-    template<typename Iter>
-    class enumerator<Iter, std::enable_if_t<blt::meta::is_forward_iterator_v<Iter>, std::void_t<std::forward_iterator_tag>>>
-            : public iterator::iterator_storage_base<iterator::enumerate_wrapper<Iter>, enumerator<Iter>>
+    template<typename T>
+    static inline auto iterate(const T& container)
     {
-        public:
-            explicit enumerator(Iter begin, Iter end, blt::size_t container_size):
-                    iterator::iterator_storage_base<iterator::enumerate_wrapper<Iter>, enumerator<Iter>>
-                            {iterator::enumerate_wrapper<Iter>{std::move(begin), 0},
-                             iterator::enumerate_wrapper<Iter>{std::move(end), container_size}}
-            {}
-            
-            explicit enumerator(Iter begin, Iter end, blt::size_t begin_index, blt::size_t end_index):
-                    iterator::iterator_storage_base<iterator::enumerate_wrapper<Iter>, enumerator<Iter>>{
-                            iterator::enumerate_wrapper<Iter>{std::move(begin), begin_index},
-                            iterator::enumerate_wrapper<Iter>{std::move(end), end_index}}
-            {}
-    };
-    
-    /**
-     * Enumerator specialization for bidirectional iterators
-     */
-    template<typename Iter>
-    class enumerator<Iter, std::enable_if_t<blt::meta::is_bidirectional_iterator_v<Iter>, std::void_t<std::bidirectional_iterator_tag>>>
-            : public iterator::iterator_storage_reversible<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>
-    {
-        public:
-            explicit enumerator(Iter begin, Iter end, blt::size_t container_size):
-                    iterator::iterator_storage_reversible<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>
-                            {iterator::enumerate_wrapper<Iter>{std::move(begin), 0},
-                             iterator::enumerate_wrapper<Iter>{std::move(end), container_size}}
-            {}
-            
-            explicit enumerator(Iter begin, Iter end, blt::size_t begin_index, blt::size_t end_index):
-                    iterator::iterator_storage_reversible<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>{
-                            iterator::enumerate_wrapper<Iter>{std::move(begin), begin_index},
-                            iterator::enumerate_wrapper<Iter>{std::move(end), end_index}}
-            {}
-    };
-    
-    /**
-     * Enumerator specialization for random access iterators
-     */
-    template<typename Iter>
-    class enumerator<Iter, std::enable_if_t<blt::meta::is_random_access_iterator_v<Iter>, std::void_t<std::random_access_iterator_tag>>>
-            : public iterator::iterator_storage_random_access<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>
-    {
-        public:
-            explicit enumerator(Iter begin, Iter end, blt::size_t container_size):
-                    iterator::iterator_storage_random_access<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>
-                            {iterator::enumerate_wrapper<Iter>{std::move(begin), 0},
-                             iterator::enumerate_wrapper<Iter>{std::move(end), container_size}}
-            {}
-            
-            explicit enumerator(Iter begin, Iter end, blt::size_t begin_index, blt::size_t end_index):
-                    iterator::iterator_storage_random_access<iterator::enumerate_wrapper<Iter>, enumerator<Iter>, enumerator_rev<Iter>>{
-                            iterator::enumerate_wrapper<Iter>{std::move(begin), begin_index},
-                            iterator::enumerate_wrapper<Iter>{std::move(end), end_index}}
-            {}
-    };
-    
-    /**
-     * Reverse enumerator specialization for bidirectional iterators
-     */
-    template<typename Iter>
-    class enumerator_rev<Iter, std::enable_if_t<blt::meta::is_bidirectional_iterator_v<Iter>, std::void_t<std::bidirectional_iterator_tag>>>
-            : public iterator::iterator_storage_reversible_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>
-    {
-        public:
-            explicit enumerator_rev(Iter begin, Iter end, blt::size_t container_size):
-                    iterator::iterator_storage_reversible_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>
-                            {std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{iterator::enumerate_wrapper<Iter>{std::move(begin), 0}},
-                             std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{
-                                     iterator::enumerate_wrapper<Iter>{std::move(end), container_size}}}
-            {}
-            
-            explicit enumerator_rev(Iter begin, Iter end, blt::size_t begin_index, blt::size_t end_index):
-                    iterator::iterator_storage_reversible_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>{
-                            std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{
-                                    iterator::enumerate_wrapper<Iter>{std::move(begin), begin_index}},
-                            std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{iterator::enumerate_wrapper<Iter>{std::move(end), end_index}}}
-            {}
-    };
-    
-    /**
-     * Reverse enumerator specialization for random access iterators
-     */
-    template<typename Iter>
-    class enumerator_rev<Iter, std::enable_if_t<blt::meta::is_random_access_iterator_v<Iter>, std::void_t<std::random_access_iterator_tag>>>
-            : public iterator::iterator_storage_random_access_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>
-    {
-        public:
-            explicit enumerator_rev(Iter begin, Iter end, blt::size_t container_size):
-                    iterator::iterator_storage_random_access_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>
-                            {std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{iterator::enumerate_wrapper<Iter>{std::move(begin), 0}},
-                             std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{
-                                     iterator::enumerate_wrapper<Iter>{std::move(end), container_size}}}
-            {}
-            
-            explicit enumerator_rev(Iter begin, Iter end, blt::size_t begin_index, blt::size_t end_index):
-                    iterator::iterator_storage_random_access_rev<std::reverse_iterator<iterator::enumerate_wrapper<Iter>>, enumerator<Iter>, enumerator_rev<Iter>>{
-                            std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{
-                                    iterator::enumerate_wrapper<Iter>{std::move(begin), begin_index}},
-                            std::reverse_iterator<iterator::enumerate_wrapper<Iter>>{iterator::enumerate_wrapper<Iter>{std::move(end), end_index}}}
-            {}
-    };
-    
-    // CTAD for enumerators
-    
-    template<typename Iter>
-    enumerator(Iter, Iter) -> enumerator<Iter>;
-    
-    template<typename Iter>
-    enumerator(Iter, Iter, blt::size_t) -> enumerator<Iter>;
-    
-    template<typename Iter>
-    enumerator(Iter, Iter, blt::size_t, blt::size_t) -> enumerator<Iter>;
-    
-    template<typename Iter1, typename Iter2>
-    class pair_iterator<Iter1, Iter2,
-            std::enable_if_t<
-                    blt::meta::is_forward_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                    std::void_t<std::forward_iterator_tag>>>
-            : public iterator::iterator_storage_base<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>>,
-              public iterator::enumerator_convertible<pair_iterator<Iter1, Iter2>, enumerator<iterator::pair_wrapper<Iter1, Iter2>>>
-    {
-        public:
-            explicit pair_iterator(Iter1 begin1, Iter1 end1, Iter2 begin2, Iter2 end2):
-                    iterator::iterator_storage_base<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>>
-                            {iterator::pair_wrapper<Iter1, Iter2>{std::move(begin1), std::move(begin2)},
-                             iterator::pair_wrapper<Iter1, Iter2>{std::move(end1), std::move(end2)}}
-            {}
-    };
-    
-    template<typename Iter1, typename Iter2>
-    class pair_iterator<Iter1, Iter2,
-            std::enable_if_t<
-                    blt::meta::is_bidirectional_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                    std::void_t<std::bidirectional_iterator_tag>>>
-            : public iterator::iterator_storage_reversible<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>,
-              public iterator::enumerator_convertible<pair_iterator<Iter1, Iter2>, enumerator<iterator::pair_wrapper<Iter1, Iter2>>>
-    {
-        public:
-            explicit pair_iterator(Iter1 begin1, Iter1 end1, Iter2 begin2, Iter2 end2):
-                    iterator::iterator_storage_reversible<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>
-                            {iterator::pair_wrapper<Iter1, Iter2>{std::move(begin1), std::move(begin2)},
-                             iterator::pair_wrapper<Iter1, Iter2>{std::move(end1), std::move(end2)}}
-            {}
-    };
-    
-    template<typename Iter1, typename Iter2>
-    class pair_iterator<Iter1, Iter2,
-            std::enable_if_t<
-                    blt::meta::is_random_access_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                    std::void_t<std::random_access_iterator_tag>>>
-            : public iterator::iterator_storage_random_access<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>,
-              public iterator::enumerator_convertible<pair_iterator<Iter1, Iter2>, enumerator<iterator::pair_wrapper<Iter1, Iter2>>>
-    {
-        public:
-            explicit pair_iterator(Iter1 begin1, Iter1 end1, Iter2 begin2, Iter2 end2):
-                    iterator::iterator_storage_random_access<iterator::pair_wrapper<Iter1, Iter2>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>
-                            {iterator::pair_wrapper<Iter1, Iter2>{std::move(begin1), std::move(begin2)},
-                             iterator::pair_wrapper<Iter1, Iter2>{std::move(end1), std::move(end2)}}
-            {}
-    };
-    
-    template<typename Iter1, typename Iter2>
-    class pair_iterator_rev<Iter1, Iter2,
-            std::enable_if_t<
-                    blt::meta::is_bidirectional_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                    std::void_t<std::bidirectional_iterator_tag>>>
-            : public iterator::iterator_storage_reversible_rev<std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>,
-              public iterator::enumerator_convertible<pair_iterator<Iter1, Iter2>, enumerator<iterator::pair_wrapper<Iter1, Iter2>>>
-    {
-        public:
-            explicit pair_iterator_rev(Iter1 begin1, Iter1 end1, Iter2 begin2, Iter2 end2):
-                    iterator::iterator_storage_reversible_rev<std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>
-                            {std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>{
-                                    iterator::pair_wrapper<Iter1, Iter2>{std::move(begin1), std::move(begin2)}},
-                             std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>{
-                                     iterator::pair_wrapper<Iter1, Iter2>{std::move(end1), std::move(end2)}}}
-            {}
-    };
-    
-    template<typename Iter1, typename Iter2>
-    class pair_iterator_rev<Iter1, Iter2,
-            std::enable_if_t<
-                    blt::meta::is_random_access_iterator_category_v<blt::meta::lowest_iterator_category_t<Iter1, Iter2>>,
-                    std::void_t<std::random_access_iterator_tag>>>
-            : public iterator::iterator_storage_random_access_rev<std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>,
-              public iterator::enumerator_convertible<pair_iterator<Iter1, Iter2>, enumerator<iterator::pair_wrapper<Iter1, Iter2>>>
-    {
-        public:
-            explicit pair_iterator_rev(Iter1 begin1, Iter1 end1, Iter2 begin2, Iter2 end2):
-                    iterator::iterator_storage_random_access_rev<std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>, pair_iterator<Iter1, Iter2>, pair_iterator_rev<Iter1, Iter2>>
-                            {std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>{
-                                    iterator::pair_wrapper<Iter1, Iter2>{std::move(begin1), std::move(begin2)}},
-                             std::reverse_iterator<iterator::pair_wrapper<Iter1, Iter2>>{
-                                     iterator::pair_wrapper<Iter1, Iter2>{std::move(end1), std::move(end2)}}}
-            {}
-    };
-    
-    // CTAD for pair iterators
-    
-    template<typename Iter1, typename Iter2>
-    pair_iterator(Iter1, Iter1, Iter2, Iter2) -> pair_iterator<Iter1, Iter2>;
-    
-    template<typename T, blt::size_t size>
-    static inline auto enumerate(const T(& container)[size])
-    {
-        return enumerator{&container[0], &container[size], size};
+        return iterator::iterator_container<decltype(container.begin())>{container.begin(), container.end()};
     }
     
     template<typename T, blt::size_t size>
-    static inline auto enumerate(T(& container)[size])
+    static inline auto iterate(const T(& container)[size])
     {
-        return enumerator{&container[0], &container[size], size};
+        return iterator::iterator_container<decltype(container.begin())>{&container[0], &container[size]};
     }
     
-    template<typename T>
-    static inline auto enumerate(T& container)
+    template<typename T, blt::size_t size>
+    static inline auto iterate(T(& container)[size])
     {
-        return enumerator{container.begin(), container.end(), container.size()};
+        return iterator::iterator_container<decltype(container.begin())>{&container[0], &container[size]};
     }
-    
-    template<typename T>
-    static inline auto enumerate(T&& container)
-    {
-        return enumerator{container.begin(), container.end(), container.size()};
-    }
-    
-    template<typename T>
-    static inline auto enumerate(const T& container)
-    {
-        return enumerator{container.begin(), container.end(), container.size()};
-    }
-    
-    template<typename T, typename G>
-    static inline auto in_pairs(const T& container1, const G& container2)
-    {
-        return pair_iterator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-    }
-    
-    template<typename T, typename G>
-    static inline auto in_pairs(T& container1, G& container2)
-    {
-        return pair_iterator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-    }
-    
-    template<typename T, typename G, blt::size_t size>
-    static inline auto in_pairs(const T(& container1)[size], const G(& container2)[size])
-    {
-        return pair_iterator{&container1[0], &container1[size], &container2[0], &container2[size]};
-    }
-    
-    template<typename T, typename G, blt::size_t size>
-    static inline auto in_pairs(T(& container1)[size], G(& container2)[size])
-    {
-        return pair_iterator{&container1[0], &container1[size], &container2[0], &container2[size]};
-    }
-    
-    template<typename T, typename G>
-    static inline auto in_pairs(T&& container1, G&& container2)
-    {
-        return pair_iterator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-    }
-    
+
 }
 
 #endif //BLT_ITERATOR_H

include/blt/iterator/zip.h

@@ -20,8 +20,6 @@
 #define BLT_ITERATOR_ZIP
 
 #include <blt/iterator/common.h>
-#include <blt/meta/meta.h>
-#include <blt/meta/iterator.h>
 #include <tuple>
 
 namespace blt
@@ -57,21 +55,20 @@ namespace blt
                 
                 zip_wrapper& operator--()
                 {
+                    static_assert(meta::is_bidirectional_or_better_category_v<iterator_category>, "Iterator must be bidirectional or better!");
                     std::apply([](auto& ... i) { ((--i), ...); }, this->iter);
                     return *this;
                 }
                 
                 friend zip_wrapper operator+(const zip_wrapper& a, blt::ptrdiff_t n)
                 {
-                    static_assert(std::is_same_v<iterator_category, std::random_access_iterator_tag>,
-                                  "Iterator must allow random access");
+                    static_assert(meta::is_random_access_iterator_category_v<iterator_category>, "Iterator must allow random access");
                     return std::apply([n](auto& ... i) { return zip_wrapper((i + n)...); }, a.iter);
                 }
                 
                 friend zip_wrapper operator-(const zip_wrapper& a, blt::ptrdiff_t n)
                 {
-                    static_assert(std::is_same_v<iterator_category, std::random_access_iterator_tag>,
-                                  "Iterator must allow random access");
+                    static_assert(meta::is_random_access_iterator_category_v<iterator_category>, "Iterator must allow random access");
                     return std::apply([n](auto& ... i) { return zip_wrapper((i - n)...); }, a.iter);
                 }
                 
@@ -97,56 +94,44 @@ namespace blt
                     return min;
                 }
         };
-
-//        template<typename Iter>
-//        struct zip_wrapper<Iter> : public Iter
-//        {
-//            using iterator_category = typename std::iterator_traits<Iter>::iterator_category;
-//            using value_type = typename std::iterator_traits<Iter>::value_type;
-//            using difference_type = typename std::iterator_traits<Iter>::difference_type;
-//            using pointer = typename std::iterator_traits<Iter>::pointer;
-//            using reference = typename std::iterator_traits<Iter>::reference;
-//
-//            using Iter::Iter;
-//        };
+        
+        template<typename Iter>
+        struct iterator_pair
+        {
+            using type = Iter;
+            
+            iterator_pair(Iter begin, Iter end): begin(std::move(begin)), end(std::move(end))
+            {}
+            
+            Iter begin;
+            Iter end;
+        };
     }
     
-    template<typename Iter>
-    struct iterator_pair
-    {
-        using type = Iter;
-        
-        iterator_pair(Iter begin, Iter end): begin(std::move(begin)), end(std::move(end))
-        {}
-        
-        Iter begin;
-        Iter end;
-    };
-    
     template<typename... Iter>
     class zip_iterator_container : public iterator::iterator_container<iterator::zip_wrapper<Iter...>>
     {
         public:
             using iterator::iterator_container<iterator::zip_wrapper<Iter...>>::iterator_container;
             
-            explicit zip_iterator_container(iterator_pair<Iter>... iterator_pairs):
+            explicit zip_iterator_container(iterator::iterator_pair<Iter>... iterator_pairs):
                     iterator::iterator_container<iterator::zip_wrapper<Iter...>>(iterator::zip_wrapper<Iter...>{std::move(iterator_pairs.begin)...},
                                                                                  iterator::zip_wrapper<Iter...>{std::move(iterator_pairs.end)...})
             {}
         
     };
     
-    namespace impl
+    namespace iterator::impl
     {
         template<typename Derived>
         class zip_t
         {
             public:
                 template<typename... Iter>
-                auto zip(iterator_pair<Iter>... iterator_pairs)
+                auto zip(iterator::iterator_pair<Iter>... iterator_pairs)
                 {
                     auto* d = static_cast<Derived*>(this);
-                    return zip_iterator_container(iterator_pair<decltype(d->begin())>{d->begin(), d->end()}, iterator_pairs...);
+                    return zip_iterator_container(iterator::iterator_pair<decltype(d->begin())>{d->begin(), d->end()}, iterator_pairs...);
                 }
         };
     }
@@ -156,7 +141,7 @@ namespace blt
      */
     
     template<typename... Iter>
-    zip_iterator_container(iterator_pair<Iter>...) -> zip_iterator_container<Iter...>;
+    zip_iterator_container(iterator::iterator_pair<Iter>...) -> zip_iterator_container<Iter...>;
     
     template<typename... Iter>
     zip_iterator_container(std::initializer_list<Iter>...) -> zip_iterator_container<Iter...>;
@@ -169,8 +154,43 @@ namespace blt
     template<typename... Container>
     auto zip(Container& ... container)
     {
-        return zip_iterator_container{iterator_pair{container.begin(), container.end()}...};
+        return zip_iterator_container{iterator::iterator_pair{std::begin(container), std::end(container)}...};
     }
+    
+    template<typename... Container>
+    auto zip(const Container& ... container)
+    {
+        return zip_iterator_container{iterator::iterator_pair{std::begin(container), std::end(container)}...};
+    }
+    
+    template<typename T, typename G>
+    static inline auto in_pairs(const T& container1, const G& container2)
+    {
+        return zip_iterator_container{iterator::iterator_pair{container1.begin(), container1.end()},
+                                      iterator::iterator_pair{container2.begin(), container2.end()}};
+    }
+    
+    template<typename T, typename G>
+    static inline auto in_pairs(T& container1, G& container2)
+    {
+        return zip_iterator_container{iterator::iterator_pair{container1.begin(), container1.end()},
+                                      iterator::iterator_pair{container2.begin(), container2.end()}};
+    }
+    
+    template<typename T, typename G, blt::size_t size>
+    static inline auto in_pairs(const T(& container1)[size], const G(& container2)[size])
+    {
+        return zip_iterator_container{iterator::iterator_pair{&container1[0], &container1[size]},
+                                      iterator::iterator_pair{&container2[0], &container2[size]}};
+    }
+    
+    template<typename T, typename G, blt::size_t size>
+    static inline auto in_pairs(T(& container1)[size], G(& container2)[size])
+    {
+        return zip_iterator_container{iterator::iterator_pair{&container1[0], &container1[size]},
+                                      iterator::iterator_pair{&container2[0], &container2[size]}};
+    }
+    
 }
 
 #endif //BLT_ITERATOR_ZIP

include/blt/math/matrix.h

@@ -122,7 +122,7 @@ namespace blt
                 return *this;
             }
             
-            constexpr generalized_matrix<T, columns, rows> transpose() const
+            [[nodiscard]] constexpr generalized_matrix<T, columns, rows> transpose() const
             {
                 generalized_matrix<T, columns, rows> mat;
                 
@@ -135,7 +135,7 @@ namespace blt
                 return mat;
             }
             
-            T magnitude() const
+            [[nodiscard]] constexpr T magnitude() const
             {
                 T ret{};
                 for (blt::u32 i = 0; i < columns; i++)
@@ -146,7 +146,7 @@ namespace blt
                 return std::sqrt(ret);
             }
             
-            matrix_t normalize() const
+            [[nodiscard]] constexpr matrix_t normalize() const
             {
                 auto mag = magnitude();
                 matrix_t mat = *this;
@@ -155,6 +155,14 @@ namespace blt
                 return mat / mag;
             }
             
+            [[nodiscard]] constexpr matrix_t abs() const
+            {
+                matrix_t copy = *this;
+                for (auto& v : copy.data)
+                    v = v.abs();
+                return copy;
+            }
+            
             constexpr inline const blt::vec<T, rows>& operator[](u32 column) const
             {
                 return data[column];
@@ -179,7 +187,7 @@ namespace blt
              * Takes a value stored across a row, taking one from each column in the specified row
              * @param row the row to extract from. defaults to the first row
              */
-            constexpr inline vec<T, columns> vec_from_column_row(blt::u32 row = 0) const
+            [[nodiscard]] constexpr inline vec<T, columns> vec_from_column_row(blt::u32 row = 0) const
             {
                 vec<T, columns> ret;
                 for (blt::u32 j = 0; j < columns; j++)
@@ -187,21 +195,6 @@ namespace blt
                 return ret;
             }
             
-            /**
-             * Assign to this matrix from the row information in each column of a matrix
-             * Where columns can be assigned directly from each-other, row stored data must be assigned this way
-             * this was hacked together for an assignment and a better way is a TODO;
-             * @param to_column column in this matrix to assign to
-             * @param row the row place that the value is store in to assign from. Defaults to the first element in each column
-             */
-            template<blt::u32 p>
-            constexpr inline matrix_t& assign_to_column_from_column_rows(generalized_matrix<T, p, rows> mat, blt::u32 to_column, blt::u32 row = 0)
-            {
-                for (blt::u32 j = 0; j < rows; j++)
-                    data[to_column][j] = mat[j][row];
-                return *this;
-            }
-            
             constexpr inline matrix_t& operator+=(const matrix_t& other)
             {
                 for (blt::u32 i = 0; i < columns; i++)
@@ -363,6 +356,16 @@ namespace blt
             {
                 return !(left == right);
             }
+            
+            auto begin() const
+            {
+                return data.begin();
+            }
+            
+            auto end() const
+            {
+                return data.end();
+            }
         
         private:
             blt::vec<T, rows> data[columns];

include/blt/math/vectors.h

@@ -124,6 +124,14 @@ namespace blt
                 return elements[3];
             }
             
+            [[nodiscard]] constexpr inline vec<T, size> abs() const
+            {
+                auto copy = *this;
+                for (auto& v : copy.elements)
+                    v = std::abs(v);
+                return copy;
+            }
+            
             [[nodiscard]] constexpr inline T magnitude() const
             {
                 T total = 0;

include/blt/meta/iterator.h

@@ -122,7 +122,8 @@ namespace blt::meta
     
     template<typename Iter>
     struct is_reverse_iterator<std::reverse_iterator<Iter>> : std::true_type
-    {};
+    {
+    };
     
     template<typename Iter>
     inline constexpr bool is_reverse_iterator_v = is_reverse_iterator<Iter>::value;

include/blt/std/ranges.h

@@ -19,151 +19,6 @@
 
 namespace blt
 {
-    namespace itr
-    {
-        template<typename Begin, typename End>
-        class itr_container
-        {
-            public:
-                itr_container(Begin&& begin, End&& end): begin_(std::forward<Begin>(begin)), end_(std::forward<End>(end))
-                {}
-                
-                Begin begin()
-                {
-                    return begin_;
-                }
-                
-                End end()
-                {
-                    return end_;
-                }
-            
-            private:
-                Begin begin_;
-                End end_;
-        };
-        
-        // TODO: cleanup! all of this! add support for reversing
-        template<typename C1_TYPE, typename C2_TYPE>
-        class pair_iterator
-        {
-            public:
-                using c1_ref = blt::meta::deref_return_t<C1_TYPE>;
-                using c2_ref = blt::meta::deref_return_t<C2_TYPE>;
-                
-                using iterator_category = std::forward_iterator_tag;
-                using value_type = std::pair<c1_ref, c2_ref>;
-                using difference_type = blt::ptrdiff_t;
-                using pointer = void*;
-                using reference = value_type&;
-                using const_reference = const value_type&;
-                
-                explicit pair_iterator(C1_TYPE c1, C2_TYPE c2): current_c1_iter(c1), current_c2_iter(c2)
-                {}
-                
-                pair_iterator& operator++()
-                {
-                    ++current_c1_iter;
-                    ++current_c2_iter;
-                    return *this;
-                }
-                
-                bool operator==(pair_iterator other) const
-                {
-                    return current_c1_iter == other.current_c1_iter && current_c2_iter == other.current_c2_iter;
-                }
-                
-                bool operator!=(pair_iterator other) const
-                {
-                    return current_c1_iter != other.current_c1_iter || current_c2_iter != other.current_c2_iter;
-                }
-                
-                value_type operator*() const
-                {
-                    return {*current_c1_iter, *current_c2_iter};
-                };
-                
-                value_type operator*()
-                {
-                    return {*current_c1_iter, *current_c2_iter};
-                };
-            
-            private:
-                C1_TYPE current_c1_iter;
-                C2_TYPE current_c2_iter;
-        };
-    }
-    
-    template<typename Begin, typename End>
-    static inline auto iterate(Begin&& begin, End&& end)
-    {
-        return itr::itr_container<Begin, End>{std::forward<Begin>(begin), std::forward<End>(end)};
-    }
-    
-    template<typename Begin, typename End>
-    static inline auto reverse_iterate(Begin&& begin, End&& end)
-    {
-        return itr::itr_container{std::reverse_iterator(std::forward<Begin>(end)), std::reverse_iterator(std::forward<End>(begin))};
-    }
-    
-    template<typename C1_ITER, typename C2_ITER, template<typename, typename> typename iterator = itr::pair_iterator>
-    class pair_enumerator
-    {
-        public:
-            explicit pair_enumerator(C1_ITER c1_begin, C1_ITER c1_end, C2_ITER c2_begin, C2_ITER c2_end):
-                    begin_(std::move(c1_begin), std::move(c2_begin)), end_(std::move(c1_end), std::move(c2_end))
-            {
-                auto size_c1 = c1_end - c1_begin;
-                auto size_c2 = c2_end - c2_begin;
-                if (size_c1 != size_c2)
-                    throw std::runtime_error("Iterator sizes don't match!");
-            }
-            
-            iterator<C1_ITER, C2_ITER> begin()
-            {
-                return begin_;
-            }
-            
-            iterator<C1_ITER, C2_ITER> end()
-            {
-                return end_;
-            }
-        
-        private:
-            iterator<C1_ITER, C2_ITER> begin_;
-            iterator<C1_ITER, C2_ITER> end_;
-    };
-    
-//    template<typename T, typename G>
-//    static inline auto in_pairs(const T& container1, const G& container2)
-//    {
-//        return pair_enumerator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-//    }
-//
-//    template<typename T, typename G>
-//    static inline auto in_pairs(T& container1, G& container2)
-//    {
-//        return pair_enumerator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-//    }
-//
-//    template<typename T, typename G, blt::size_t size>
-//    static inline auto in_pairs(const T(& container1)[size], const G(& container2)[size])
-//    {
-//        return pair_enumerator{&container1[0], &container1[size], &container2[0], &container2[size]};
-//    }
-//
-//    template<typename T, typename G, blt::size_t size>
-//    static inline auto in_pairs(T(& container1)[size], G(& container2)[size])
-//    {
-//        return pair_enumerator{&container1[0], &container1[size], &container2[0], &container2[size]};
-//    }
-//
-//    template<typename T, typename G>
-//    static inline auto in_pairs(T&& container1, G&& container2)
-//    {
-//        return pair_enumerator{container1.begin(), container1.end(), container2.begin(), container2.end()};
-//    }
-    
     template<typename T>
     struct range
     {
@@ -239,41 +94,6 @@ namespace blt
             }
     };
     
-    template<typename I>
-    class itr_offset
-    {
-        private:
-            I begin_;
-            I end_;
-        public:
-            template<typename T>
-            itr_offset(I begin, I end, T offset): begin_(begin), end_(end)
-            {
-                for (T t = 0; t < offset; t++)
-                    ++begin_;
-            }
-            
-            template<typename C, typename T>
-            itr_offset(C& container, T offset): begin_(container.begin()), end_(container.end())
-            {
-                for (T t = 0; t < offset; t++)
-                    ++begin_;
-            }
-            
-            auto begin()
-            {
-                return begin_;
-            }
-            
-            auto end()
-            {
-                return end_;
-            }
-    };
-    
-    template<typename C, typename T>
-    itr_offset(C, T) -> itr_offset<typename C::iterator>;
-    
     inline constexpr std::size_t dynamic_extent = std::numeric_limits<std::size_t>::max();
     
     template<typename T, std::size_t extent = dynamic_extent>

tests/iterator_tests.cpp

@@ -23,6 +23,7 @@
 #include <blt/iterator/zip.h>
 #include <blt/iterator/enumerate.h>
 #include <blt/iterator/iterator.h>
+#include <blt/std/ranges.h>
 #include <blt/format/boxing.h>
 #include <array>
 #include <forward_list>
@@ -122,6 +123,10 @@ void test_enumerate()
 void test_pairs()
 {
     blt::log_box_t box(std::cout, "Pairs Tests", 25);
+    for (auto [a1, a2] : blt::in_pairs(array_1, array_2))
+    {
+        BLT_TRACE_STREAM << a1 << " : " << a2 << "\n";
+    }
 }
 
 void test_zip()
@@ -158,6 +163,41 @@ void test_zip()
     }
 }
 
+void test_iterate()
+{
+    blt::log_box_t box(std::cout, "Iterate Tests", 25);
+    for (auto v : blt::iterate(array_1))
+    {
+        BLT_TRACE_STREAM << "Element: " << v << "\n";
+    }
+    BLT_TRACE("================================");
+    for (auto v : blt::iterate(array_1).skip(5))
+    {
+        BLT_TRACE_STREAM << "Element: " << v << "\n";
+    }
+    BLT_TRACE("================================");
+    for (auto v : blt::iterate(array_1).take(5))
+    {
+        BLT_TRACE_STREAM << "Element: " << v << "\n";
+    }
+    BLT_TRACE("================================");
+    for (auto v : blt::iterate(array_1).rev())
+    {
+        BLT_TRACE_STREAM << "Element: " << v << "\n";
+    }
+    BLT_TRACE("================================");
+    for (auto [a, b] : blt::iterate(array_1).zip(list_1))
+    {
+        BLT_TRACE_STREAM << "Zip: " << a << " " << b << "\n";
+    }
+    BLT_TRACE("================================");
+    for (auto [i, data] : blt::iterate(array_1).zip(list_1).skip(3).take(4).enumerate())
+    {
+        auto [a, b] = data;
+        BLT_TRACE_STREAM << "Zip (" << i << "): " << a << " " << b << "\n";
+    }
+}
+
 int main()
 {
     test_enumerate();
@@ -165,4 +205,6 @@ int main()
     test_pairs();
     std::cout << std::endl;
     test_zip();
+    std::cout << std::endl;
+    test_iterate();
 }