abs in vec/mat

include/blt/iterator/iter_common.h

@@ -0,0 +1,30 @@
+#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_ITER_COMMON
+#define BLT_ITERATOR_ITER_COMMON
+
+#include <type_traits>
+#include <iterator>
+
+namespace blt
+{
+
+}
+
+#endif //BLT_ITERATOR_ITER_COMMON

include/blt/iterator/iterator.h

@@ -0,0 +1,885 @@
+#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_H
+#define BLT_ITERATOR_H
+
+#include <blt/std/types.h>
+#include <blt/std/logging.h>
+#include <blt/iterator/iter_common.h>
+#include <blt/iterator/zip.h>
+#include <blt/meta/meta.h>
+#include <blt/meta/iterator.h>
+#include <type_traits>
+#include <iterator>
+#include <tuple>
+
+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 Iter, typename = std::void_t<>>
+        class enumerate_wrapper;
+        
+        template<typename Iter1, typename Iter2, typename = std::void_t<>>
+        class pair_wrapper;
+        
+        template<typename Tag, typename... Iter>
+        class zip_wrapper;
+        
+        template<typename Tag, typename... Iter>
+        class zip_iterator_storage;
+        
+        template<typename Tag, typename... Iter>
+        class zip_iterator_storage_rev;
+        
+        template<typename... Iter>
+        class zip_forward_iterator
+        {
+            public:
+                explicit zip_forward_iterator(Iter... iter): iter(std::make_tuple(iter...))
+                {}
+                
+                std::tuple<blt::meta::deref_return_t<Iter>...> operator*() const
+                {
+                    return std::apply([](auto& ... i) { return std::make_tuple(*i...); }, iter);
+                }
+                
+                friend bool operator==(const zip_forward_iterator& a, const zip_forward_iterator& b)
+                {
+                    return a.iter == b.iter;
+                }
+                
+                friend bool operator!=(const zip_forward_iterator& a, const zip_forward_iterator& b)
+                {
+                    return !(a.iter == b.iter);
+                }
+                
+                zip_forward_iterator& operator++()
+                {
+                    std::apply([](auto& ... i) { ((++i), ...); }, iter);
+                    return *this;
+                }
+                
+                zip_forward_iterator operator++(int)
+                {
+                    auto tmp = *this;
+                    ++*this;
+                    return tmp;
+                }
+                
+                auto base()
+                {
+                    return iter;
+                }
+            
+            protected:
+                std::tuple<Iter...> iter;
+        };
+        
+        template<typename... Iter>
+        class zip_bidirectional_iterator : public zip_forward_iterator<Iter...>
+        {
+            public:
+                using zip_forward_iterator<Iter...>::zip_forward_iterator;
+                
+                zip_bidirectional_iterator& operator--()
+                {
+                    std::apply([](auto& ... i) { ((--i), ...); }, this->iter);
+                    return *this;
+                }
+                
+                zip_bidirectional_iterator operator--(int)
+                {
+                    auto tmp = *this;
+                    --*this;
+                    return tmp;
+                }
+        };
+        
+        template<typename... Iter>
+        class zip_wrapper<std::forward_iterator_tag, Iter...> : public zip_forward_iterator<Iter...>
+        {
+            public:
+                using zip_forward_iterator<Iter...>::zip_forward_iterator;
+                
+                using iterator_category = std::forward_iterator_tag;
+                using value_type = std::tuple<blt::meta::deref_return_t<Iter>...>;
+                using difference_type = blt::ptrdiff_t;
+                using pointer = value_type;
+                using reference = value_type;
+        };
+        
+        template<typename... Iter>
+        class zip_wrapper<std::bidirectional_iterator_tag, Iter...> : public zip_bidirectional_iterator<Iter...>
+        {
+            public:
+                using zip_bidirectional_iterator<Iter...>::zip_bidirectional_iterator;
+                
+                using iterator_category = std::bidirectional_iterator_tag;
+                using value_type = std::tuple<blt::meta::deref_return_t<Iter>...>;
+                using difference_type = blt::ptrdiff_t;
+                using pointer = value_type;
+                using reference = value_type;
+        };
+        
+        template<typename... Iter>
+        class zip_wrapper<std::random_access_iterator_tag, Iter...> : public zip_bidirectional_iterator<Iter...>
+        {
+            public:
+                using zip_bidirectional_iterator<Iter...>::zip_bidirectional_iterator;
+                
+                using iterator_category = std::bidirectional_iterator_tag;
+                using value_type = std::tuple<blt::meta::deref_return_t<Iter>...>;
+                using difference_type = blt::ptrdiff_t;
+                using pointer = value_type;
+                using reference = value_type;
+        };
+        
+        /**
+         * 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()))};
+                }
+        };
+        
+        template<typename... Iter>
+        class zip_iterator_storage<std::forward_iterator_tag, Iter...>
+        {
+        
+        };
+        
+        template<typename... Iter>
+        class zip_iterator_storage<std::bidirectional_iterator_tag, Iter...>
+        {
+        
+        };
+        
+        template<typename... Iter>
+        class zip_iterator_storage<std::random_access_iterator_tag, Iter...>
+        {
+        
+        };
+        
+    }
+    
+    /**
+     * 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>>
+    {
+        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};
+    }
+    
+    template<typename T, blt::size_t size>
+    static inline auto enumerate(T(& container)[size])
+    {
+        return enumerator{&container[0], &container[size], 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(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

@@ -0,0 +1,30 @@
+#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_ZIP
+#define BLT_ITERATOR_ZIP
+
+#include <blt/iterator/iter_common.h>
+#include <tuple>
+
+namespace blt
+{
+
+}
+
+#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;