fix meta

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
-set(BLT_VERSION 0.20.17)
+set(BLT_VERSION 0.20.18)
 set(BLT_TEST_VERSION 0.0.1)
 
 set(BLT_TARGET BLT)

include/blt/meta/meta.h

@@ -189,6 +189,38 @@ namespace blt::meta
     template<typename T, typename Or>
     using const_reference_t = decltype(detail::const_reference_type_helper<Or>::template get<T>(0));
     
+    template<typename T>
+    struct arrow_return
+    {
+        using type = typename std::result_of<decltype(&T::operator->)(T*)>::type;
+    };
+    
+    template<typename T>
+    struct arrow_return<T*>
+    {
+        using type = T*;
+    };
+    
+    // gets the return type for arrow operator
+    template<typename T>
+    using arrow_return_t = typename arrow_return<T>::type;
+    
+    template<typename T>
+    struct deref_return
+    {
+        using type = typename std::result_of<decltype(&T::operator*)(T*)>::type;
+    };
+    
+    template<typename T>
+    struct deref_return<T*>
+    {
+        using type = T&;
+    };
+    
+    // gets the return type for the reference operator
+    template<typename T>
+    using deref_return_t = typename deref_return<T>::type;
+
 #define BLT_META_MAKE_FUNCTION_CHECK(FUNC, ...)\
     template<typename T, typename = void> \
     class has_func_##FUNC : public std::false_type \

include/blt/std/ranges.h

@@ -82,23 +82,24 @@ namespace blt
                     return current != other.current;
                 }
                 
-                std::pair<blt::size_t, const_reference> operator*() const
+                std::pair<blt::size_t, blt::meta::deref_return_t<TYPE_ITR>> operator*() const
                 {
                     return {index, *current};
                 };
                 
-                std::pair<blt::size_t, reference> operator*()
+                std::pair<blt::size_t, blt::meta::deref_return_t<TYPE_ITR>> operator*()
                 {
                     return {index, *current};
                 };
         };
         
+        // TODO: cleanup! all of this! add support for reversing
         template<typename C1_TYPE, typename C2_TYPE>
         class pair_iterator
         {
             public:
-                using c1_ref = typename std::iterator_traits<C1_TYPE>::reference;
+                using c1_ref = blt::meta::deref_return_t<C1_TYPE>;
-                using c2_ref = typename std::iterator_traits<C2_TYPE>::reference;
+                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>;