Merge pull request #26662 from neikeq/csharp-collection-changes

C#: Collections breaking changes and improvements

18 files changed, 647 insertions, 294 deletions

diff --git a/modules/mono/csharp_script.cpp b/modules/mono/csharp_script.cpp
index dfdb4a0b3a..5f97069485 100644
--- a/modules/mono/csharp_script.cpp
+++ b/modules/mono/csharp_script.cpp
@@ -571,7 +571,7 @@ Vector<ScriptLanguage::StackInfo> CSharpLanguage::stack_trace_get_info(MonoObjec
 
 	MonoException *exc = NULL;
 
-	MonoArray *frames = invoke_method_thunk(CACHED_METHOD_THUNK(System_Diagnostics_StackTrace, GetFrames), p_stack_trace, (MonoObject **)&exc);
+	MonoArray *frames = invoke_method_thunk(CACHED_METHOD_THUNK(System_Diagnostics_StackTrace, GetFrames), p_stack_trace, &exc);
 
 	if (exc) {
 		GDMonoUtils::debug_print_unhandled_exception(exc);
@@ -595,7 +595,7 @@ Vector<ScriptLanguage::StackInfo> CSharpLanguage::stack_trace_get_info(MonoObjec
 		MonoString *file_name;
 		int file_line_num;
 		MonoString *method_decl;
-		invoke_method_thunk(get_sf_info, frame, &file_name, &file_line_num, &method_decl, (MonoObject **)&exc);
+		invoke_method_thunk(get_sf_info, frame, &file_name, &file_line_num, &method_decl, &exc);
 
 		if (exc) {
 			GDMonoUtils::debug_print_unhandled_exception(exc);
@@ -625,7 +625,7 @@ void CSharpLanguage::frame() {
 
 			if (task_scheduler) {
 				MonoException *exc = NULL;
-				invoke_method_thunk(CACHED_METHOD_THUNK(GodotTaskScheduler, Activate), task_scheduler, (MonoObject **)&exc);
+				invoke_method_thunk(CACHED_METHOD_THUNK(GodotTaskScheduler, Activate), task_scheduler, &exc);
 
 				if (exc) {
 					GDMonoUtils::debug_unhandled_exception(exc);
@@ -2166,7 +2166,8 @@ bool CSharpScript::_get_member_export(GDMonoClass *p_class, IMonoClassMember *p_
 		CRASH_NOW();
 	}
 
-	Variant::Type variant_type = GDMonoMarshal::managed_to_variant_type(type);
+	GDMonoMarshal::ExportInfo export_info;
+	Variant::Type variant_type = GDMonoMarshal::managed_to_variant_type(type, &export_info);
 
 	if (!p_member->has_attribute(CACHED_CLASS(ExportAttribute))) {
 		r_prop_info = PropertyInfo(variant_type, name.operator String(), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_SCRIPT_VARIABLE);
@@ -2191,6 +2192,7 @@ bool CSharpScript::_get_member_export(GDMonoClass *p_class, IMonoClassMember *p_
 		ERR_PRINTS("Unknown type of exported member: " + p_class->get_full_name() + "." + name.operator String());
 		return false;
 	} else if (variant_type == Variant::INT && type.type_encoding == MONO_TYPE_VALUETYPE && mono_class_is_enum(type.type_class->get_mono_ptr())) {
+		// TODO: Move to ExportInfo?
 		variant_type = Variant::INT;
 		hint = PROPERTY_HINT_ENUM;
 
@@ -2257,6 +2259,11 @@ bool CSharpScript::_get_member_export(GDMonoClass *p_class, IMonoClassMember *p_
 
 		hint = PROPERTY_HINT_RESOURCE_TYPE;
 		hint_string = NATIVE_GDMONOCLASS_NAME(field_native_class);
+	} else if (variant_type == Variant::ARRAY && export_info.array.element_type != Variant::NIL) {
+		hint = PROPERTY_HINT_TYPE_STRING;
+		hint_string = itos(export_info.array.element_type) + ":";
+	} else if (variant_type == Variant::DICTIONARY && export_info.dictionary.key_type != Variant::NIL && export_info.dictionary.value_type != Variant::NIL) {
+		// TODO: There is no hint for this yet
 	} else {
 		hint = PropertyHint(CACHED_FIELD(ExportAttribute, hint)->get_int_value(attr));
 		hint_string = CACHED_FIELD(ExportAttribute, hintString)->get_string_value(attr);
diff --git a/modules/mono/glue/Managed/Files/Array.cs b/modules/mono/glue/Managed/Files/Array.cs
index 1ee64f3b71..2277c7bf18 100644
--- a/modules/mono/glue/Managed/Files/Array.cs
+++ b/modules/mono/glue/Managed/Files/Array.cs
@@ -28,7 +28,7 @@ namespace Godot.Collections
         }
     }
 
-    public class Array : IList<object>, ICollection<object>, IEnumerable<object>, IDisposable
+    public class Array : IList, IDisposable
     {
         ArraySafeHandle safeHandle;
         bool disposed = false;
@@ -38,6 +38,14 @@ namespace Godot.Collections
             safeHandle = new ArraySafeHandle(godot_icall_Array_Ctor());
         }
 
+        public Array(IEnumerable collection) : this()
+        {
+            if (collection == null)
+                throw new NullReferenceException($"Parameter '{nameof(collection)} cannot be null.'");
+
+            MarshalUtils.EnumerableToArray(collection, GetPtr());
+        }
+
         internal Array(ArraySafeHandle handle)
         {
             safeHandle = handle;
@@ -56,6 +64,13 @@ namespace Godot.Collections
             return safeHandle.DangerousGetHandle();
         }
 
+        public Error Resize(int newSize)
+        {
+            return godot_icall_Array_Resize(GetPtr(), newSize);
+        }
+
+        // IDisposable
+
         public void Dispose()
         {
             if (disposed)
@@ -70,62 +85,55 @@ namespace Godot.Collections
             disposed = true;
         }
 
+        // IList
+
+        public bool IsReadOnly => false;
+
+        public bool IsFixedSize => false;
+
         public object this[int index]
         {
-            get
-            {
-                return godot_icall_Array_At(GetPtr(), index);
-            }
-            set
-            {
-                godot_icall_Array_SetAt(GetPtr(), index, value);
-            }
+            get => godot_icall_Array_At(GetPtr(), index);
+            set => godot_icall_Array_SetAt(GetPtr(), index, value);
         }
 
-        public int Count
-        {
-            get
-            {
-                return godot_icall_Array_Count(GetPtr());
-            }
-        }
+        public int Add(object value) => godot_icall_Array_Add(GetPtr(), value);
 
-        public bool IsReadOnly
-        {
-            get
-            {
-                return false;
-            }
-        }
+        public bool Contains(object value) => godot_icall_Array_Contains(GetPtr(), value);
 
-        public void Add(object item)
-        {
-            godot_icall_Array_Add(GetPtr(), item);
-        }
+        public void Clear() => godot_icall_Array_Clear(GetPtr());
 
-        public void Clear()
-        {
-            godot_icall_Array_Clear(GetPtr());
-        }
+        public int IndexOf(object value) => godot_icall_Array_IndexOf(GetPtr(), value);
 
-        public bool Contains(object item)
-        {
-            return godot_icall_Array_Contains(GetPtr(), item);
-        }
+        public void Insert(int index, object value) => godot_icall_Array_Insert(GetPtr(), index, value);
+
+        public void Remove(object value) => godot_icall_Array_Remove(GetPtr(), value);
+
+        public void RemoveAt(int index) => godot_icall_Array_RemoveAt(GetPtr(), index);
+
+        // ICollection
+
+        public int Count => godot_icall_Array_Count(GetPtr());
+
+        public object SyncRoot => this;
 
-        public void CopyTo(object[] array, int arrayIndex)
+        public bool IsSynchronized => false;
+
+        public void CopyTo(System.Array array, int index)
         {
             if (array == null)
                 throw new ArgumentNullException(nameof(array), "Value cannot be null.");
 
-            if (arrayIndex < 0)
-                throw new ArgumentOutOfRangeException(nameof(arrayIndex), "Number was less than the array's lower bound in the first dimension.");
+            if (index < 0)
+                throw new ArgumentOutOfRangeException(nameof(index), "Number was less than the array's lower bound in the first dimension.");
 
             // Internal call may throw ArgumentException
-            godot_icall_Array_CopyTo(GetPtr(), array, arrayIndex);
+            godot_icall_Array_CopyTo(GetPtr(), array, index);
         }
 
-        public IEnumerator<object> GetEnumerator()
+        // IEnumerable
+
+        public IEnumerator GetEnumerator()
         {
             int count = Count;
 
@@ -135,36 +143,6 @@ namespace Godot.Collections
             }
         }
 
-        public int IndexOf(object item)
-        {
-            return godot_icall_Array_IndexOf(GetPtr(), item);
-        }
-
-        public void Insert(int index, object item)
-        {
-            godot_icall_Array_Insert(GetPtr(), index, item);
-        }
-
-        public bool Remove(object item)
-        {
-            return godot_icall_Array_Remove(GetPtr(), item);
-        }
-
-        public void RemoveAt(int index)
-        {
-            godot_icall_Array_RemoveAt(GetPtr(), index);
-        }
-
-        public Error Resize(int newSize)
-        {
-            return godot_icall_Array_Resize(GetPtr(), newSize);
-        }
-
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return GetEnumerator();
-        }
-
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal extern static IntPtr godot_icall_Array_Ctor();
 
@@ -184,7 +162,7 @@ namespace Godot.Collections
         internal extern static int godot_icall_Array_Count(IntPtr ptr);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
-        internal extern static void godot_icall_Array_Add(IntPtr ptr, object item);
+        internal extern static int godot_icall_Array_Add(IntPtr ptr, object item);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal extern static void godot_icall_Array_Clear(IntPtr ptr);
@@ -193,7 +171,7 @@ namespace Godot.Collections
         internal extern static bool godot_icall_Array_Contains(IntPtr ptr, object item);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
-        internal extern static void godot_icall_Array_CopyTo(IntPtr ptr, object[] array, int arrayIndex);
+        internal extern static void godot_icall_Array_CopyTo(IntPtr ptr, System.Array array, int arrayIndex);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal extern static int godot_icall_Array_IndexOf(IntPtr ptr, object item);
@@ -231,6 +209,14 @@ namespace Godot.Collections
             objectArray = new Array();
         }
 
+        public Array(IEnumerable<T> collection)
+        {
+            if (collection == null)
+                throw new NullReferenceException($"Parameter '{nameof(collection)} cannot be null.'");
+
+            objectArray = new Array(collection);
+        }
+
         public Array(Array array)
         {
             objectArray = array;
@@ -246,11 +232,23 @@ namespace Godot.Collections
             objectArray = new Array(handle);
         }
 
+        internal IntPtr GetPtr()
+        {
+            return objectArray.GetPtr();
+        }
+
         public static explicit operator Array(Array<T> from)
         {
             return from.objectArray;
         }
 
+        public Error Resize(int newSize)
+        {
+            return objectArray.Resize(newSize);
+        }
+
+        // IList<T>
+
         public T this[int index]
         {
             get
@@ -263,6 +261,23 @@ namespace Godot.Collections
             }
         }
 
+        public int IndexOf(T item)
+        {
+            return objectArray.IndexOf(item);
+        }
+
+        public void Insert(int index, T item)
+        {
+            objectArray.Insert(index, item);
+        }
+
+        public void RemoveAt(int index)
+        {
+            objectArray.RemoveAt(index);
+        }
+
+        // ICollection<T>
+
         public int Count
         {
             get
@@ -317,6 +332,13 @@ namespace Godot.Collections
             }
         }
 
+        public bool Remove(T item)
+        {
+            return Array.godot_icall_Array_Remove(GetPtr(), item);
+        }
+
+        // IEnumerable<T>
+
         public IEnumerator<T> GetEnumerator()
         {
             int count = objectArray.Count;
@@ -327,39 +349,9 @@ namespace Godot.Collections
             }
         }
 
-        public int IndexOf(T item)
-        {
-            return objectArray.IndexOf(item);
-        }
-
-        public void Insert(int index, T item)
-        {
-            objectArray.Insert(index, item);
-        }
-
-        public bool Remove(T item)
-        {
-            return objectArray.Remove(item);
-        }
-
-        public void RemoveAt(int index)
-        {
-            objectArray.RemoveAt(index);
-        }
-
-        public Error Resize(int newSize)
-        {
-            return objectArray.Resize(newSize);
-        }
-
         IEnumerator IEnumerable.GetEnumerator()
         {
             return GetEnumerator();
         }
-
-        internal IntPtr GetPtr()
-        {
-            return objectArray.GetPtr();
-        }
     }
 }
diff --git a/modules/mono/glue/Managed/Files/Dictionary.cs b/modules/mono/glue/Managed/Files/Dictionary.cs
index fb4521065f..af1782b79a 100644
--- a/modules/mono/glue/Managed/Files/Dictionary.cs
+++ b/modules/mono/glue/Managed/Files/Dictionary.cs
@@ -29,9 +29,7 @@ namespace Godot.Collections
     }
 
     public class Dictionary :
-        IDictionary<object, object>,
-        ICollection<KeyValuePair<object, object>>,
-        IEnumerable<KeyValuePair<object, object>>,
+        IDictionary,
         IDisposable
     {
         DictionarySafeHandle safeHandle;
@@ -42,6 +40,14 @@ namespace Godot.Collections
             safeHandle = new DictionarySafeHandle(godot_icall_Dictionary_Ctor());
         }
 
+        public Dictionary(IDictionary dictionary) : this()
+        {
+            if (dictionary == null)
+                throw new NullReferenceException($"Parameter '{nameof(dictionary)} cannot be null.'");
+
+            MarshalUtils.IDictionaryToDictionary(dictionary, GetPtr());
+        }
+
         internal Dictionary(DictionarySafeHandle handle)
         {
             safeHandle = handle;
@@ -74,19 +80,9 @@ namespace Godot.Collections
             disposed = true;
         }
 
-        public object this[object key]
-        {
-            get
-            {
-                return godot_icall_Dictionary_GetValue(GetPtr(), key);
-            }
-            set
-            {
-                godot_icall_Dictionary_SetValue(GetPtr(), key, value);
-            }
-        }
+        // IDictionary
 
-        public ICollection<object> Keys
+        public ICollection Keys
         {
             get
             {
@@ -95,7 +91,7 @@ namespace Godot.Collections
             }
         }
 
-        public ICollection<object> Values
+        public ICollection Values
         {
             get
             {
@@ -104,97 +100,97 @@ namespace Godot.Collections
             }
         }
 
-        public int Count
-        {
-            get
-            {
-                return godot_icall_Dictionary_Count(GetPtr());
-            }
-        }
+        public bool IsFixedSize => false;
 
-        public bool IsReadOnly
-        {
-            get
-            {
-                return false;
-            }
-        }
+        public bool IsReadOnly => false;
 
-        public void Add(object key, object value)
+        public object this[object key]
         {
-            godot_icall_Dictionary_Add(GetPtr(), key, value);
+            get => godot_icall_Dictionary_GetValue(GetPtr(), key);
+            set => godot_icall_Dictionary_SetValue(GetPtr(), key, value);
         }
 
-        public void Add(KeyValuePair<object, object> item)
-        {
-            Add(item.Key, item.Value);
-        }
+        public void Add(object key, object value) => godot_icall_Dictionary_Add(GetPtr(), key, value);
 
-        public void Clear()
-        {
-            godot_icall_Dictionary_Clear(GetPtr());
-        }
+        public void Clear() => godot_icall_Dictionary_Clear(GetPtr());
 
-        public bool Contains(KeyValuePair<object, object> item)
-        {
-            return godot_icall_Dictionary_Contains(GetPtr(), item.Key, item.Value);
-        }
+        public bool Contains(object key) => godot_icall_Dictionary_ContainsKey(GetPtr(), key);
 
-        public bool ContainsKey(object key)
-        {
-            return godot_icall_Dictionary_ContainsKey(GetPtr(), key);
-        }
+        public IDictionaryEnumerator GetEnumerator() => new DictionaryEnumerator(this);
+
+        public void Remove(object key) => godot_icall_Dictionary_RemoveKey(GetPtr(), key);
+
+        // ICollection
+
+        public object SyncRoot => this;
 
-        public void CopyTo(KeyValuePair<object, object>[] array, int arrayIndex)
+        public bool IsSynchronized => false;
+
+        public int Count => godot_icall_Dictionary_Count(GetPtr());
+
+        public void CopyTo(System.Array array, int index)
         {
-            // TODO 3 internal calls, can reduce to 1
+            // TODO Can be done with single internal call
+
+            if (array == null)
+                throw new ArgumentNullException(nameof(array), "Value cannot be null.");
+
+            if (index < 0)
+                throw new ArgumentOutOfRangeException(nameof(index), "Number was less than the array's lower bound in the first dimension.");
+
             Array keys = (Array)Keys;
             Array values = (Array)Values;
             int count = Count;
 
+            if (array.Length < (index + count))
+                throw new ArgumentException("Destination array was not long enough. Check destIndex and length, and the array's lower bounds.");
+
             for (int i = 0; i < count; i++)
             {
-                // TODO 2 internal calls, can reduce to 1
-                array[arrayIndex] = new KeyValuePair<object, object>(keys[i], values[i]);
-                arrayIndex++;
+                array.SetValue(new DictionaryEntry(keys[i], values[i]), index);
+                index++;
             }
         }
 
-        public IEnumerator<KeyValuePair<object, object>> GetEnumerator()
+        // IEnumerable
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+        private class DictionaryEnumerator : IDictionaryEnumerator
         {
-            // TODO 3 internal calls, can reduce to 1
-            Array keys = (Array)Keys;
-            Array values = (Array)Values;
-            int count = Count;
+            Array keys;
+            Array values;
+            int count;
+            int index = -1;
 
-            for (int i = 0; i < count; i++)
+            public DictionaryEnumerator(Dictionary dictionary)
             {
-                // TODO 2 internal calls, can reduce to 1
-                yield return new KeyValuePair<object, object>(keys[i], values[i]);
+                // TODO 3 internal calls, can reduce to 1
+                keys = (Array)dictionary.Keys;
+                values = (Array)dictionary.Values;
+                count = dictionary.Count;
             }
-        }
 
-        public bool Remove(object key)
-        {
-            return godot_icall_Dictionary_RemoveKey(GetPtr(), key);
-        }
+            public object Current => Entry;
 
-        public bool Remove(KeyValuePair<object, object> item)
-        {
-            return godot_icall_Dictionary_Remove(GetPtr(), item.Key, item.Value);
-        }
+            public DictionaryEntry Entry =>
+                // TODO 2 internal calls, can reduce to 1
+                new DictionaryEntry(keys[index], values[index]);
 
-        public bool TryGetValue(object key, out object value)
-        {
-            object retValue;
-            bool found = godot_icall_Dictionary_TryGetValue(GetPtr(), key, out retValue);
-            value = found ? retValue : default(object);
-            return found;
-        }
+            public object Key => Entry.Key;
 
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return GetEnumerator();
+            public object Value => Entry.Value;
+
+            public bool MoveNext()
+            {
+                index++;
+                return index < count;
+            }
+
+            public void Reset()
+            {
+                index = -1;
+            }
         }
 
         [MethodImpl(MethodImplOptions.InternalCall)]
@@ -250,9 +246,7 @@ namespace Godot.Collections
     }
 
     public class Dictionary<TKey, TValue> :
-        IDictionary<TKey, TValue>,
-        ICollection<KeyValuePair<TKey, TValue>>,
-        IEnumerable<KeyValuePair<TKey, TValue>>
+        IDictionary<TKey, TValue>
     {
         Dictionary objectDict;
 
@@ -269,6 +263,23 @@ namespace Godot.Collections
             objectDict = new Dictionary();
         }
 
+        public Dictionary(IDictionary<TKey, TValue> dictionary)
+        {
+            objectDict = new Dictionary();
+
+            if (dictionary == null)
+                throw new NullReferenceException($"Parameter '{nameof(dictionary)} cannot be null.'");
+
+            // TODO: Can be optimized
+
+            IntPtr godotDictionaryPtr = GetPtr();
+
+            foreach (KeyValuePair<TKey, TValue> entry in dictionary)
+            {
+                Dictionary.godot_icall_Dictionary_Add(godotDictionaryPtr, entry.Key, entry.Value);
+            }
+        }
+
         public Dictionary(Dictionary dictionary)
         {
             objectDict = dictionary;
@@ -289,6 +300,13 @@ namespace Godot.Collections
             return from.objectDict;
         }
 
+        internal IntPtr GetPtr()
+        {
+            return objectDict.GetPtr();
+        }
+
+        // IDictionary<TKey, TValue>
+
         public TValue this[TKey key]
         {
             get
@@ -319,6 +337,31 @@ namespace Godot.Collections
             }
         }
 
+        public void Add(TKey key, TValue value)
+        {
+            objectDict.Add(key, value);
+        }
+
+        public bool ContainsKey(TKey key)
+        {
+            return objectDict.Contains(key);
+        }
+
+        public bool Remove(TKey key)
+        {
+            return Dictionary.godot_icall_Dictionary_RemoveKey(GetPtr(), key);
+        }
+
+        public bool TryGetValue(TKey key, out TValue value)
+        {
+            object retValue;
+            bool found = Dictionary.godot_icall_Dictionary_TryGetValue_Generic(GetPtr(), key, out retValue, valTypeEncoding, valTypeClass);
+            value = found ? (TValue)retValue : default(TValue);
+            return found;
+        }
+
+        // ICollection<KeyValuePair<TKey, TValue>>
+
         public int Count
         {
             get
@@ -335,11 +378,6 @@ namespace Godot.Collections
             }
         }
 
-        public void Add(TKey key, TValue value)
-        {
-            objectDict.Add(key, value);
-        }
-
         public void Add(KeyValuePair<TKey, TValue> item)
         {
             objectDict.Add(item.Key, item.Value);
@@ -355,18 +393,22 @@ namespace Godot.Collections
             return objectDict.Contains(new KeyValuePair<object, object>(item.Key, item.Value));
         }
 
-        public bool ContainsKey(TKey key)
-        {
-            return objectDict.ContainsKey(key);
-        }
-
         public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
         {
+            if (array == null)
+                throw new ArgumentNullException(nameof(array), "Value cannot be null.");
+
+            if (arrayIndex < 0)
+                throw new ArgumentOutOfRangeException(nameof(arrayIndex), "Number was less than the array's lower bound in the first dimension.");
+
             // TODO 3 internal calls, can reduce to 1
             Array<TKey> keys = (Array<TKey>)Keys;
             Array<TValue> values = (Array<TValue>)Values;
             int count = Count;
 
+            if (array.Length < (arrayIndex + count))
+                throw new ArgumentException("Destination array was not long enough. Check destIndex and length, and the array's lower bounds.");
+
             for (int i = 0; i < count; i++)
             {
                 // TODO 2 internal calls, can reduce to 1
@@ -375,6 +417,13 @@ namespace Godot.Collections
             }
         }
 
+        public bool Remove(KeyValuePair<TKey, TValue> item)
+        {
+            return Dictionary.godot_icall_Dictionary_Remove(GetPtr(), item.Key, item.Value); ;
+        }
+
+        // IEnumerable<KeyValuePair<TKey, TValue>>
+
         public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
         {
             // TODO 3 internal calls, can reduce to 1
@@ -389,32 +438,9 @@ namespace Godot.Collections
             }
         }
 
-        public bool Remove(TKey key)
-        {
-            return objectDict.Remove(key);
-        }
-
-        public bool Remove(KeyValuePair<TKey, TValue> item)
-        {
-            return objectDict.Remove(new KeyValuePair<object, object>(item.Key, item.Value));
-        }
-
-        public bool TryGetValue(TKey key, out TValue value)
-        {
-            object retValue;
-            bool found = Dictionary.godot_icall_Dictionary_TryGetValue_Generic(GetPtr(), key, out retValue, valTypeEncoding, valTypeClass);
-            value = found ? (TValue)retValue : default(TValue);
-            return found;
-        }
-
         IEnumerator IEnumerable.GetEnumerator()
         {
             return GetEnumerator();
         }
-
-        internal IntPtr GetPtr()
-        {
-            return objectDict.GetPtr();
-        }
     }
 }
diff --git a/modules/mono/glue/Managed/Files/MarshalUtils.cs b/modules/mono/glue/Managed/Files/MarshalUtils.cs
index f7699a15bf..7e72b0edb5 100644
--- a/modules/mono/glue/Managed/Files/MarshalUtils.cs
+++ b/modules/mono/glue/Managed/Files/MarshalUtils.cs
@@ -1,18 +1,68 @@
 using System;
-using Godot.Collections;
+using System.Collections;
 
 namespace Godot
 {
+    using Array = Godot.Collections.Array;
+    using Dictionary = Godot.Collections.Dictionary;
+
     static class MarshalUtils
     {
-        static bool IsArrayGenericType(Type type)
+        static bool TypeIsGenericArray(Type type)
         {
-            return type.GetGenericTypeDefinition() == typeof(Array<>);
+            return type.GetGenericTypeDefinition() == typeof(Godot.Collections.Array<>);
+        }
+
+        static bool TypeIsGenericDictionary(Type type)
+        {
+            return type.GetGenericTypeDefinition() == typeof(Godot.Collections.Dictionary<,>);
+        }
+
+        static void ArrayGetElementType(Type type, out Type elementType)
+        {
+            elementType = type.GetGenericArguments()[0];
+        }
+
+        static void DictionaryGetKeyValueTypes(Type type, out Type keyType, out Type valueType)
+        {
+            var genericArgs = type.GetGenericArguments();
+
+            keyType = genericArgs[0];
+            valueType = genericArgs[1];
+        }
+
+        // TODO Add support for IEnumerable<T> and IDictionary<TKey, TValue>
+        // TODO: EnumerableToArray and IDictionaryToDictionary can be optimized
+
+        internal static void EnumerableToArray(IEnumerable enumerable, IntPtr godotArrayPtr)
+        {
+            if (enumerable is ICollection collection)
+            {
+                int count = collection.Count;
+
+                object[] tempArray = new object[count];
+                collection.CopyTo(tempArray, 0);
+
+                for (int i = 0; i < count; i++)
+                {
+                    Array.godot_icall_Array_Add(godotArrayPtr, tempArray[i]);
+                }
+            }
+            else
+            {
+                foreach (object element in enumerable)
+                {
+                    Array.godot_icall_Array_Add(godotArrayPtr, element);
+                }
+            }
         }
 
-        static bool IsDictionaryGenericType(Type type)
+        internal static void IDictionaryToDictionary(IDictionary dictionary, IntPtr godotDictionaryPtr)
         {
-            return type.GetGenericTypeDefinition() == typeof(Dictionary<, >);
+            foreach (DictionaryEntry entry in dictionary)
+            {
+                Dictionary.godot_icall_Dictionary_Add(godotDictionaryPtr, entry.Key, entry.Value);
+            }
         }
     }
 }
diff --git a/modules/mono/glue/Managed/IgnoredFiles/Variant.cs b/modules/mono/glue/Managed/IgnoredFiles/Variant.cs
new file mode 100644
index 0000000000..802140b062
--- /dev/null
+++ b/modules/mono/glue/Managed/IgnoredFiles/Variant.cs
@@ -0,0 +1,11 @@
+
+namespace Godot
+{
+    public static class Variant
+    {
+        public enum Type
+        {
+
+        }
+    }
+}
diff --git a/modules/mono/glue/collections_glue.cpp b/modules/mono/glue/collections_glue.cpp
index 1aad1c53bc..84c3f354d8 100644
--- a/modules/mono/glue/collections_glue.cpp
+++ b/modules/mono/glue/collections_glue.cpp
@@ -73,8 +73,9 @@ int godot_icall_Array_Count(Array *ptr) {
 	return ptr->size();
 }
 
-void godot_icall_Array_Add(Array *ptr, MonoObject *item) {
+int godot_icall_Array_Add(Array *ptr, MonoObject *item) {
 	ptr->append(GDMonoMarshal::mono_object_to_variant(item));
+	return ptr->size();
 }
 
 void godot_icall_Array_Clear(Array *ptr) {
diff --git a/modules/mono/glue/collections_glue.h b/modules/mono/glue/collections_glue.h
index 85a2e243a2..69768500d8 100644
--- a/modules/mono/glue/collections_glue.h
+++ b/modules/mono/glue/collections_glue.h
@@ -51,7 +51,7 @@ void godot_icall_Array_SetAt(Array *ptr, int index, MonoObject *value);
 
 int godot_icall_Array_Count(Array *ptr);
 
-void godot_icall_Array_Add(Array *ptr, MonoObject *item);
+int godot_icall_Array_Add(Array *ptr, MonoObject *item);
 
 void godot_icall_Array_Clear(Array *ptr);
 
diff --git a/modules/mono/mono_gd/gd_mono_class.cpp b/modules/mono/mono_gd/gd_mono_class.cpp
index 92324d73f9..4342f46109 100644
--- a/modules/mono/mono_gd/gd_mono_class.cpp
+++ b/modules/mono/mono_gd/gd_mono_class.cpp
@@ -55,7 +55,8 @@ String GDMonoClass::get_full_name() const {
 }
 
 MonoType *GDMonoClass::get_mono_type() {
-	// Care, you cannot compare MonoType pointers
+	// Careful, you cannot compare two MonoType*.
+	// There is mono_metadata_type_equal, how is this different from comparing two MonoClass*?
 	return get_mono_type(mono_class);
 }
 
@@ -260,6 +261,11 @@ bool GDMonoClass::has_fetched_method_unknown_params(const StringName &p_name) {
 	return get_fetched_method_unknown_params(p_name) != NULL;
 }
 
+bool GDMonoClass::implements_interface(GDMonoClass *p_interface) {
+
+	return mono_class_implements_interface(mono_class, p_interface->get_mono_ptr());
+}
+
 GDMonoMethod *GDMonoClass::get_method(const StringName &p_name, int p_params_count) {
 
 	MethodKey key = MethodKey(p_name, p_params_count);
diff --git a/modules/mono/mono_gd/gd_mono_class.h b/modules/mono/mono_gd/gd_mono_class.h
index 4af909450e..249422b844 100644
--- a/modules/mono/mono_gd/gd_mono_class.h
+++ b/modules/mono/mono_gd/gd_mono_class.h
@@ -135,6 +135,8 @@ public:
 	void fetch_attributes();
 	void fetch_methods_with_godot_api_checks(GDMonoClass *p_native_base);
 
+	bool implements_interface(GDMonoClass *p_interface);
+
 	GDMonoMethod *get_method(const StringName &p_name, int p_params_count = 0);
 	GDMonoMethod *get_method(MonoMethod *p_raw_method);
 	GDMonoMethod *get_method(MonoMethod *p_raw_method, const StringName &p_name);
diff --git a/modules/mono/mono_gd/gd_mono_field.cpp b/modules/mono/mono_gd/gd_mono_field.cpp
index 5e9d4db122..9779797d1a 100644
--- a/modules/mono/mono_gd/gd_mono_field.cpp
+++ b/modules/mono/mono_gd/gd_mono_field.cpp
@@ -313,6 +313,18 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 				break;
 			}
 
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				MonoObject *managed = GDMonoUtils::create_managed_from(p_value.operator Dictionary(), CACHED_CLASS(Dictionary));
+				mono_field_set_value(p_object, mono_field, managed);
+				break;
+			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				MonoObject *managed = GDMonoUtils::create_managed_from(p_value.operator Array(), CACHED_CLASS(Array));
+				mono_field_set_value(p_object, mono_field, managed);
+				break;
+			}
+
 			ERR_EXPLAIN(String() + "Attempted to set the value of a field of unmarshallable type: " + type_class->get_name());
 			ERR_FAIL();
 		} break;
@@ -422,8 +434,8 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 
 			MonoException *exc = NULL;
 
-			GDMonoUtils::IsDictionaryGenericType type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, IsDictionaryGenericType);
-			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericDictionary type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericDictionary);
+			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_dict) {
@@ -434,8 +446,8 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 
 			exc = NULL;
 
-			GDMonoUtils::IsArrayGenericType type_is_array = CACHED_METHOD_THUNK(MarshalUtils, IsArrayGenericType);
-			MonoBoolean is_array = invoke_method_thunk(type_is_array, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericArray type_is_array = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericArray);
+			MonoBoolean is_array = invoke_method_thunk(type_is_array, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_array) {
@@ -443,6 +455,18 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 				mono_field_set_value(p_object, mono_field, managed);
 				break;
 			}
+
+			if (type.type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				MonoObject *managed = GDMonoUtils::create_managed_from(p_value.operator Dictionary(), CACHED_CLASS(Dictionary));
+				mono_field_set_value(p_object, mono_field, managed);
+				break;
+			}
+
+			if (type.type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				MonoObject *managed = GDMonoUtils::create_managed_from(p_value.operator Array(), CACHED_CLASS(Array));
+				mono_field_set_value(p_object, mono_field, managed);
+				break;
+			}
 		} break;
 
 		default: {
diff --git a/modules/mono/mono_gd/gd_mono_header.h b/modules/mono/mono_gd/gd_mono_header.h
index dd8c047386..d7962eac8b 100644
--- a/modules/mono/mono_gd/gd_mono_header.h
+++ b/modules/mono/mono_gd/gd_mono_header.h
@@ -35,24 +35,12 @@
 
 class GDMonoAssembly;
 class GDMonoClass;
-class IMonoClassMember;
 class GDMonoField;
-class GDMonoProperty;
 class GDMonoMethod;
+class GDMonoProperty;
 
-struct ManagedType {
-	int type_encoding;
-	GDMonoClass *type_class;
-
-	ManagedType() :
-			type_encoding(0),
-			type_class(NULL) {
-	}
+class IMonoClassMember;
 
-	ManagedType(int p_type_encoding, GDMonoClass *p_type_class) :
-			type_encoding(p_type_encoding),
-			type_class(p_type_class) {
-	}
-};
+#include "managed_type.h"
 
 #endif // GD_MONO_HEADER_H
diff --git a/modules/mono/mono_gd/gd_mono_marshal.cpp b/modules/mono/mono_gd/gd_mono_marshal.cpp
index 7fe8ae608a..de4f3650bd 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.cpp
+++ b/modules/mono/mono_gd/gd_mono_marshal.cpp
@@ -35,7 +35,7 @@
 
 namespace GDMonoMarshal {
 
-Variant::Type managed_to_variant_type(const ManagedType &p_type) {
+Variant::Type managed_to_variant_type(const ManagedType &p_type, ExportInfo *r_export_info) {
 	switch (p_type.type_encoding) {
 		case MONO_TYPE_BOOLEAN:
 			return Variant::BOOL;
@@ -156,26 +156,66 @@ Variant::Type managed_to_variant_type(const ManagedType &p_type) {
 			if (CACHED_CLASS(Array) == type_class) {
 				return Variant::ARRAY;
 			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				return Variant::DICTIONARY;
+			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				return Variant::ARRAY;
+			}
 		} break;
 
 		case MONO_TYPE_GENERICINST: {
 			MonoReflectionType *reftype = mono_type_get_object(SCRIPTS_DOMAIN, p_type.type_class->get_mono_type());
 
 			MonoException *exc = NULL;
-			GDMonoUtils::IsDictionaryGenericType type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, IsDictionaryGenericType);
-			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericDictionary type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericDictionary);
+			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_dict) {
+				if (r_export_info) {
+					MonoReflectionType *key_reftype;
+					MonoReflectionType *value_reftype;
+
+					exc = NULL;
+					invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, DictionaryGetKeyValueTypes),
+							reftype, &key_reftype, &value_reftype, &exc);
+					UNLIKELY_UNHANDLED_EXCEPTION(exc);
+
+					r_export_info->dictionary.key_type = managed_to_variant_type(ManagedType::from_reftype(key_reftype));
+					r_export_info->dictionary.value_type = managed_to_variant_type(ManagedType::from_reftype(value_reftype));
+				}
+
 				return Variant::DICTIONARY;
 			}
 
 			exc = NULL;
-			GDMonoUtils::IsArrayGenericType type_is_array = CACHED_METHOD_THUNK(MarshalUtils, IsArrayGenericType);
-			MonoBoolean is_array = invoke_method_thunk(type_is_array, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericArray type_is_array = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericArray);
+			MonoBoolean is_array = invoke_method_thunk(type_is_array, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_array) {
+				if (r_export_info) {
+					MonoReflectionType *elem_reftype;
+
+					exc = NULL;
+					invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, ArrayGetElementType),
+							reftype, &elem_reftype, &exc);
+					UNLIKELY_UNHANDLED_EXCEPTION(exc);
+
+					r_export_info->array.element_type = managed_to_variant_type(ManagedType::from_reftype(elem_reftype));
+				}
+
+				return Variant::ARRAY;
+			}
+
+			if (p_type.type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				return Variant::DICTIONARY;
+			}
+
+			if (p_type.type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
 				return Variant::ARRAY;
 			}
 		} break;
@@ -453,6 +493,14 @@ MonoObject *variant_to_mono_object(const Variant *p_var, const ManagedType &p_ty
 			if (CACHED_CLASS(Array) == type_class) {
 				return GDMonoUtils::create_managed_from(p_var->operator Array(), CACHED_CLASS(Array));
 			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				return GDMonoUtils::create_managed_from(p_var->operator Dictionary(), CACHED_CLASS(Dictionary));
+			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				return GDMonoUtils::create_managed_from(p_var->operator Array(), CACHED_CLASS(Array));
+			}
 		} break;
 		case MONO_TYPE_OBJECT: {
 			// Variant
@@ -548,8 +596,8 @@ MonoObject *variant_to_mono_object(const Variant *p_var, const ManagedType &p_ty
 				MonoReflectionType *reftype = mono_type_get_object(SCRIPTS_DOMAIN, p_type.type_class->get_mono_type());
 
 				MonoException *exc = NULL;
-				GDMonoUtils::IsDictionaryGenericType type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, IsDictionaryGenericType);
-				MonoBoolean is_dict = invoke_method_thunk(type_is_dict, (MonoObject *)reftype, (MonoObject **)&exc);
+				GDMonoUtils::TypeIsGenericDictionary type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericDictionary);
+				MonoBoolean is_dict = invoke_method_thunk(type_is_dict, reftype, &exc);
 				UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 				if (is_dict) {
@@ -557,13 +605,21 @@ MonoObject *variant_to_mono_object(const Variant *p_var, const ManagedType &p_ty
 				}
 
 				exc = NULL;
-				GDMonoUtils::IsArrayGenericType type_is_array = CACHED_METHOD_THUNK(MarshalUtils, IsArrayGenericType);
-				MonoBoolean is_array = invoke_method_thunk(type_is_array, (MonoObject *)reftype, (MonoObject **)&exc);
+				GDMonoUtils::TypeIsGenericArray type_is_array = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericArray);
+				MonoBoolean is_array = invoke_method_thunk(type_is_array, reftype, &exc);
 				UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 				if (is_array) {
 					return GDMonoUtils::create_managed_from(p_var->operator Array(), p_type.type_class);
 				}
+
+				if (p_type.type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+					return GDMonoUtils::create_managed_from(p_var->operator Dictionary(), CACHED_CLASS(Dictionary));
+				}
+
+				if (p_type.type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+					return GDMonoUtils::create_managed_from(p_var->operator Array(), CACHED_CLASS(Array));
+				}
 			} break;
 		} break;
 	}
@@ -577,15 +633,9 @@ Variant mono_object_to_variant(MonoObject *p_obj) {
 	if (!p_obj)
 		return Variant();
 
-	GDMonoClass *tclass = GDMono::get_singleton()->get_class(mono_object_get_class(p_obj));
-	ERR_FAIL_COND_V(!tclass, Variant());
+	ManagedType type = ManagedType::from_class(mono_object_get_class(p_obj));
 
-	MonoType *raw_type = tclass->get_mono_type();
-
-	ManagedType type;
-
-	type.type_encoding = mono_type_get_type(raw_type);
-	type.type_class = tclass;
+	ERR_FAIL_COND_V(!type.type_class, Variant());
 
 	switch (type.type_encoding) {
 		case MONO_TYPE_BOOLEAN:
@@ -717,17 +767,33 @@ Variant mono_object_to_variant(MonoObject *p_obj) {
 
 			if (CACHED_CLASS(Array) == type_class) {
 				MonoException *exc = NULL;
-				Array *ptr = invoke_method_thunk(CACHED_METHOD_THUNK(Array, GetPtr), p_obj, (MonoObject **)&exc);
+				Array *ptr = invoke_method_thunk(CACHED_METHOD_THUNK(Array, GetPtr), p_obj, &exc);
 				UNLIKELY_UNHANDLED_EXCEPTION(exc);
 				return ptr ? Variant(*ptr) : Variant();
 			}
 
 			if (CACHED_CLASS(Dictionary) == type_class) {
 				MonoException *exc = NULL;
-				Dictionary *ptr = invoke_method_thunk(CACHED_METHOD_THUNK(Dictionary, GetPtr), p_obj, (MonoObject **)&exc);
+				Dictionary *ptr = invoke_method_thunk(CACHED_METHOD_THUNK(Dictionary, GetPtr), p_obj, &exc);
 				UNLIKELY_UNHANDLED_EXCEPTION(exc);
 				return ptr ? Variant(*ptr) : Variant();
 			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				Dictionary dict;
+				MonoException *exc = NULL;
+				invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, IDictionaryToDictionary), p_obj, &dict, &exc);
+				UNLIKELY_UNHANDLED_EXCEPTION(exc);
+				return dict;
+			}
+
+			if (type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				Array array;
+				MonoException *exc = NULL;
+				invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, EnumerableToArray), p_obj, &array, &exc);
+				UNLIKELY_UNHANDLED_EXCEPTION(exc);
+				return array;
+			}
 		} break;
 
 		case MONO_TYPE_GENERICINST: {
@@ -735,8 +801,8 @@ Variant mono_object_to_variant(MonoObject *p_obj) {
 
 			MonoException *exc = NULL;
 
-			GDMonoUtils::IsDictionaryGenericType type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, IsDictionaryGenericType);
-			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericDictionary type_is_dict = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericDictionary);
+			MonoBoolean is_dict = invoke_method_thunk(type_is_dict, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_dict) {
@@ -748,8 +814,8 @@ Variant mono_object_to_variant(MonoObject *p_obj) {
 
 			exc = NULL;
 
-			GDMonoUtils::IsArrayGenericType type_is_array = CACHED_METHOD_THUNK(MarshalUtils, IsArrayGenericType);
-			MonoBoolean is_array = invoke_method_thunk(type_is_array, (MonoObject *)reftype, (MonoObject **)&exc);
+			GDMonoUtils::TypeIsGenericArray type_is_array = CACHED_METHOD_THUNK(MarshalUtils, TypeIsGenericArray);
+			MonoBoolean is_array = invoke_method_thunk(type_is_array, reftype, &exc);
 			UNLIKELY_UNHANDLED_EXCEPTION(exc);
 
 			if (is_array) {
@@ -758,6 +824,22 @@ Variant mono_object_to_variant(MonoObject *p_obj) {
 				UNLIKELY_UNHANDLED_EXCEPTION(exc);
 				return *unbox<Array *>(ret);
 			}
+
+			if (type.type_class->implements_interface(CACHED_CLASS(System_Collections_IDictionary))) {
+				Dictionary dict;
+				exc = NULL;
+				invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, IDictionaryToDictionary), p_obj, &dict, &exc);
+				UNLIKELY_UNHANDLED_EXCEPTION(exc);
+				return dict;
+			}
+
+			if (type.type_class->implements_interface(CACHED_CLASS(System_Collections_IEnumerable))) {
+				Array array;
+				exc = NULL;
+				invoke_method_thunk(CACHED_METHOD_THUNK(MarshalUtils, EnumerableToArray), p_obj, &array, &exc);
+				UNLIKELY_UNHANDLED_EXCEPTION(exc);
+				return array;
+			}
 		} break;
 	}
 
diff --git a/modules/mono/mono_gd/gd_mono_marshal.h b/modules/mono/mono_gd/gd_mono_marshal.h
index 4f86e02f87..4a73f9e3e6 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.h
+++ b/modules/mono/mono_gd/gd_mono_marshal.h
@@ -32,6 +32,7 @@
 #define GDMONOMARSHAL_H
 
 #include "core/variant.h"
+
 #include "gd_mono.h"
 #include "gd_mono_utils.h"
 
@@ -56,7 +57,25 @@ T unbox(MonoObject *p_obj) {
 #define BOX_PTR(x) mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(IntPtr), x)
 #define BOX_ENUM(m_enum_class, x) mono_value_box(mono_domain_get(), m_enum_class, &x)
 
-Variant::Type managed_to_variant_type(const ManagedType &p_type);
+// FIXME: Made this struct in a hurry. It could be done differently.
+struct ExportInfo {
+	struct ArrayInfo {
+		Variant::Type element_type;
+
+		ArrayInfo() :
+				element_type(Variant::NIL) {}
+	} array;
+	struct DictionaryInfo {
+		Variant::Type key_type;
+		Variant::Type value_type;
+
+		DictionaryInfo() :
+				key_type(Variant::NIL),
+				value_type(Variant::NIL) {}
+	} dictionary;
+};
+
+Variant::Type managed_to_variant_type(const ManagedType &p_type, ExportInfo *r_export_info = NULL);
 
 // String
 
diff --git a/modules/mono/mono_gd/gd_mono_utils.cpp b/modules/mono/mono_gd/gd_mono_utils.cpp
index 6cc1c8afc2..429d4f68d9 100644
--- a/modules/mono/mono_gd/gd_mono_utils.cpp
+++ b/modules/mono/mono_gd/gd_mono_utils.cpp
@@ -63,6 +63,7 @@ MonoCache mono_cache;
 #define CACHE_FIELD_AND_CHECK(m_class, m_field, m_val) CACHE_AND_CHECK(GDMonoUtils::mono_cache.field_##m_class##_##m_field, m_val)
 #define CACHE_METHOD_AND_CHECK(m_class, m_method, m_val) CACHE_AND_CHECK(GDMonoUtils::mono_cache.method_##m_class##_##m_method, m_val)
 #define CACHE_METHOD_THUNK_AND_CHECK(m_class, m_method, m_val) CACHE_AND_CHECK(GDMonoUtils::mono_cache.methodthunk_##m_class##_##m_method, m_val)
+#define CACHE_PROPERTY_AND_CHECK(m_class, m_property, m_val) CACHE_AND_CHECK(GDMonoUtils::mono_cache.property_##m_class##_##m_property, m_val)
 
 void MonoCache::clear_members() {
 
@@ -81,6 +82,9 @@ void MonoCache::clear_members() {
 	class_String = NULL;
 	class_IntPtr = NULL;
 
+	class_System_Collections_IEnumerable = NULL;
+	class_System_Collections_IDictionary = NULL;
+
 #ifdef DEBUG_ENABLED
 	class_System_Diagnostics_StackTrace = NULL;
 	methodthunk_System_Diagnostics_StackTrace_GetFrames = NULL;
@@ -143,12 +147,17 @@ void MonoCache::clear_members() {
 	methodthunk_GodotObject_Dispose = NULL;
 	methodthunk_Array_GetPtr = NULL;
 	methodthunk_Dictionary_GetPtr = NULL;
-	methodthunk_MarshalUtils_IsArrayGenericType = NULL;
-	methodthunk_MarshalUtils_IsDictionaryGenericType = NULL;
 	methodthunk_SignalAwaiter_SignalCallback = NULL;
 	methodthunk_SignalAwaiter_FailureCallback = NULL;
 	methodthunk_GodotTaskScheduler_Activate = NULL;
 
+	methodthunk_MarshalUtils_TypeIsGenericArray = NULL;
+	methodthunk_MarshalUtils_TypeIsGenericDictionary = NULL;
+	methodthunk_MarshalUtils_ArrayGetElementType = NULL;
+	methodthunk_MarshalUtils_DictionaryGetKeyValueTypes = NULL;
+	methodthunk_MarshalUtils_EnumerableToArray = NULL;
+	methodthunk_MarshalUtils_IDictionaryToDictionary = NULL;
+
 	task_scheduler_handle = Ref<MonoGCHandle>();
 }
 
@@ -178,6 +187,9 @@ void update_corlib_cache() {
 	CACHE_CLASS_AND_CHECK(String, GDMono::get_singleton()->get_corlib_assembly()->get_class(mono_get_string_class()));
 	CACHE_CLASS_AND_CHECK(IntPtr, GDMono::get_singleton()->get_corlib_assembly()->get_class(mono_get_intptr_class()));
 
+	CACHE_CLASS_AND_CHECK(System_Collections_IEnumerable, GDMono::get_singleton()->get_corlib_assembly()->get_class("System.Collections", "IEnumerable"));
+	CACHE_CLASS_AND_CHECK(System_Collections_IDictionary, GDMono::get_singleton()->get_corlib_assembly()->get_class("System.Collections", "IDictionary"));
+
 #ifdef DEBUG_ENABLED
 	CACHE_CLASS_AND_CHECK(System_Diagnostics_StackTrace, GDMono::get_singleton()->get_corlib_assembly()->get_class("System.Diagnostics", "StackTrace"));
 	CACHE_METHOD_THUNK_AND_CHECK(System_Diagnostics_StackTrace, GetFrames, (StackTrace_GetFrames)CACHED_CLASS(System_Diagnostics_StackTrace)->get_method_thunk("GetFrames"));
@@ -242,12 +254,17 @@ void update_godot_api_cache() {
 	CACHE_METHOD_THUNK_AND_CHECK(GodotObject, Dispose, (GodotObject_Dispose)CACHED_CLASS(GodotObject)->get_method_thunk("Dispose", 0));
 	CACHE_METHOD_THUNK_AND_CHECK(Array, GetPtr, (Array_GetPtr)GODOT_API_NS_CLAS(BINDINGS_NAMESPACE_COLLECTIONS, Array)->get_method_thunk("GetPtr", 0));
 	CACHE_METHOD_THUNK_AND_CHECK(Dictionary, GetPtr, (Dictionary_GetPtr)GODOT_API_NS_CLAS(BINDINGS_NAMESPACE_COLLECTIONS, Dictionary)->get_method_thunk("GetPtr", 0));
-	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, IsArrayGenericType, (IsArrayGenericType)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("IsArrayGenericType", 1));
-	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, IsDictionaryGenericType, (IsDictionaryGenericType)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("IsDictionaryGenericType", 1));
 	CACHE_METHOD_THUNK_AND_CHECK(SignalAwaiter, SignalCallback, (SignalAwaiter_SignalCallback)GODOT_API_CLASS(SignalAwaiter)->get_method_thunk("SignalCallback", 1));
 	CACHE_METHOD_THUNK_AND_CHECK(SignalAwaiter, FailureCallback, (SignalAwaiter_FailureCallback)GODOT_API_CLASS(SignalAwaiter)->get_method_thunk("FailureCallback", 0));
 	CACHE_METHOD_THUNK_AND_CHECK(GodotTaskScheduler, Activate, (GodotTaskScheduler_Activate)GODOT_API_CLASS(GodotTaskScheduler)->get_method_thunk("Activate", 0));
 
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, TypeIsGenericArray, (TypeIsGenericArray)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("TypeIsGenericArray", 1));
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, TypeIsGenericDictionary, (TypeIsGenericDictionary)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("TypeIsGenericDictionary", 1));
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, ArrayGetElementType, (ArrayGetElementType)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("ArrayGetElementType", 2));
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, DictionaryGetKeyValueTypes, (DictionaryGetKeyValueTypes)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("DictionaryGetKeyValueTypes", 3));
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, EnumerableToArray, (EnumerableToArray)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("EnumerableToArray", 2));
+	CACHE_METHOD_THUNK_AND_CHECK(MarshalUtils, IDictionaryToDictionary, (IDictionaryToDictionary)GODOT_API_CLASS(MarshalUtils)->get_method_thunk("IDictionaryToDictionary", 2));
+
 #ifdef DEBUG_ENABLED
 	CACHE_METHOD_THUNK_AND_CHECK(DebuggingUtils, GetStackFrameInfo, (DebugUtils_StackFrameInfo)GODOT_API_CLASS(DebuggingUtils)->get_method_thunk("GetStackFrameInfo", 4));
 #endif
@@ -712,7 +729,7 @@ uint64_t unbox_enum_value(MonoObject *p_boxed, MonoType *p_enum_basetype, bool &
 }
 
 void dispose(MonoObject *p_mono_object, MonoException **r_exc) {
-	invoke_method_thunk(CACHED_METHOD_THUNK(GodotObject, Dispose), p_mono_object, (MonoObject **)r_exc);
+	invoke_method_thunk(CACHED_METHOD_THUNK(GodotObject, Dispose), p_mono_object, r_exc);
 }
 
 } // namespace GDMonoUtils
diff --git a/modules/mono/mono_gd/gd_mono_utils.h b/modules/mono/mono_gd/gd_mono_utils.h
index e88bf1ced9..87610e286c 100644
--- a/modules/mono/mono_gd/gd_mono_utils.h
+++ b/modules/mono/mono_gd/gd_mono_utils.h
@@ -49,18 +49,21 @@
 
 namespace GDMonoUtils {
 
-typedef void (*GodotObject_Dispose)(MonoObject *, MonoObject **);
-typedef Array *(*Array_GetPtr)(MonoObject *, MonoObject **);
-typedef Dictionary *(*Dictionary_GetPtr)(MonoObject *, MonoObject **);
-typedef MonoObject *(*SignalAwaiter_SignalCallback)(MonoObject *, MonoArray *, MonoObject **);
-typedef MonoObject *(*SignalAwaiter_FailureCallback)(MonoObject *, MonoObject **);
-typedef MonoObject *(*GodotTaskScheduler_Activate)(MonoObject *, MonoObject **);
-typedef MonoArray *(*StackTrace_GetFrames)(MonoObject *, MonoObject **);
-typedef MonoBoolean (*IsArrayGenericType)(MonoObject *, MonoObject **);
-typedef MonoBoolean (*IsDictionaryGenericType)(MonoObject *, MonoObject **);
-typedef MonoBoolean (*IsArrayGenericType)(MonoObject *, MonoObject **);
-typedef MonoBoolean (*IsDictionaryGenericType)(MonoObject *, MonoObject **);
-typedef void (*DebugUtils_StackFrameInfo)(MonoObject *, MonoString **, int *, MonoString **, MonoObject **);
+typedef void (*GodotObject_Dispose)(MonoObject *, MonoException **);
+typedef Array *(*Array_GetPtr)(MonoObject *, MonoException **);
+typedef Dictionary *(*Dictionary_GetPtr)(MonoObject *, MonoException **);
+typedef MonoObject *(*SignalAwaiter_SignalCallback)(MonoObject *, MonoArray *, MonoException **);
+typedef MonoObject *(*SignalAwaiter_FailureCallback)(MonoObject *, MonoException **);
+typedef MonoObject *(*GodotTaskScheduler_Activate)(MonoObject *, MonoException **);
+typedef MonoArray *(*StackTrace_GetFrames)(MonoObject *, MonoException **);
+typedef void (*DebugUtils_StackFrameInfo)(MonoObject *, MonoString **, int *, MonoString **, MonoException **);
+
+typedef MonoBoolean (*TypeIsGenericArray)(MonoReflectionType *, MonoException **);
+typedef MonoBoolean (*TypeIsGenericDictionary)(MonoReflectionType *, MonoException **);
+typedef MonoBoolean (*ArrayGetElementType)(MonoReflectionType *, MonoReflectionType **, MonoException **);
+typedef MonoBoolean (*DictionaryGetKeyValueTypes)(MonoReflectionType *, MonoReflectionType **, MonoReflectionType **, MonoException **);
+typedef void (*EnumerableToArray)(MonoObject *, Array *, MonoException **);
+typedef void (*IDictionaryToDictionary)(MonoObject *, Dictionary *, MonoException **);
 
 struct MonoCache {
 
@@ -83,6 +86,9 @@ struct MonoCache {
 	GDMonoClass *class_String;
 	GDMonoClass *class_IntPtr;
 
+	GDMonoClass *class_System_Collections_IEnumerable;
+	GDMonoClass *class_System_Collections_IDictionary;
+
 #ifdef DEBUG_ENABLED
 	GDMonoClass *class_System_Diagnostics_StackTrace;
 	StackTrace_GetFrames methodthunk_System_Diagnostics_StackTrace_GetFrames;
@@ -146,12 +152,17 @@ struct MonoCache {
 	GodotObject_Dispose methodthunk_GodotObject_Dispose;
 	Array_GetPtr methodthunk_Array_GetPtr;
 	Dictionary_GetPtr methodthunk_Dictionary_GetPtr;
-	IsArrayGenericType methodthunk_MarshalUtils_IsArrayGenericType;
-	IsDictionaryGenericType methodthunk_MarshalUtils_IsDictionaryGenericType;
 	SignalAwaiter_SignalCallback methodthunk_SignalAwaiter_SignalCallback;
 	SignalAwaiter_FailureCallback methodthunk_SignalAwaiter_FailureCallback;
 	GodotTaskScheduler_Activate methodthunk_GodotTaskScheduler_Activate;
 
+	TypeIsGenericArray methodthunk_MarshalUtils_TypeIsGenericArray;
+	TypeIsGenericDictionary methodthunk_MarshalUtils_TypeIsGenericDictionary;
+	ArrayGetElementType methodthunk_MarshalUtils_ArrayGetElementType;
+	DictionaryGetKeyValueTypes methodthunk_MarshalUtils_DictionaryGetKeyValueTypes;
+	EnumerableToArray methodthunk_MarshalUtils_EnumerableToArray;
+	IDictionaryToDictionary methodthunk_MarshalUtils_IDictionaryToDictionary;
+
 	Ref<MonoGCHandle> task_scheduler_handle;
 
 	bool corlib_cache_updated;
@@ -255,6 +266,7 @@ void dispose(MonoObject *p_mono_object, MonoException **r_exc);
 #define CACHED_FIELD(m_class, m_field) (GDMonoUtils::mono_cache.field_##m_class##_##m_field)
 #define CACHED_METHOD(m_class, m_method) (GDMonoUtils::mono_cache.method_##m_class##_##m_method)
 #define CACHED_METHOD_THUNK(m_class, m_method) (GDMonoUtils::mono_cache.methodthunk_##m_class##_##m_method)
+#define CACHED_PROPERTY(m_class, m_property) (GDMonoUtils::mono_cache.property_##m_class##_##m_property)
 
 #ifdef REAL_T_IS_DOUBLE
 #define REAL_T_MONOCLASS CACHED_CLASS_RAW(double)
diff --git a/modules/mono/mono_gd/managed_type.cpp b/modules/mono/mono_gd/managed_type.cpp
new file mode 100644
index 0000000000..9f736b71cd
--- /dev/null
+++ b/modules/mono/mono_gd/managed_type.cpp
@@ -0,0 +1,58 @@
+/*************************************************************************/
+/*  managed_type.cpp                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "managed_type.h"
+
+#include "gd_mono.h"
+#include "gd_mono_class.h"
+
+ManagedType ManagedType::from_class(GDMonoClass *p_class) {
+	return ManagedType(mono_type_get_type(p_class->get_mono_type()), p_class);
+}
+
+ManagedType ManagedType::from_class(MonoClass *p_mono_class) {
+	GDMonoClass *tclass = GDMono::get_singleton()->get_class(p_mono_class);
+	ERR_FAIL_COND_V(!tclass, ManagedType());
+
+	return ManagedType(mono_type_get_type(tclass->get_mono_type()), tclass);
+}
+
+ManagedType ManagedType::from_type(MonoType *p_mono_type) {
+	MonoClass *mono_class = mono_class_from_mono_type(p_mono_type);
+	GDMonoClass *tclass = GDMono::get_singleton()->get_class(mono_class);
+	ERR_FAIL_COND_V(!tclass, ManagedType());
+
+	return ManagedType(mono_type_get_type(p_mono_type), tclass);
+}
+
+ManagedType ManagedType::from_reftype(MonoReflectionType *p_mono_reftype) {
+	MonoType *mono_type = mono_reflection_type_get_type(p_mono_reftype);
+	return from_type(mono_type);
+}
diff --git a/modules/mono/mono_gd/managed_type.h b/modules/mono/mono_gd/managed_type.h
new file mode 100644
index 0000000000..a537e56aea
--- /dev/null
+++ b/modules/mono/mono_gd/managed_type.h
@@ -0,0 +1,58 @@
+/*************************************************************************/
+/*  managed_type.h                                                       */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef MANAGED_TYPE_H
+#define MANAGED_TYPE_H
+
+#include <mono/metadata/object.h>
+
+#include "gd_mono_header.h"
+
+struct ManagedType {
+	int type_encoding;
+	GDMonoClass *type_class;
+
+	static ManagedType from_class(GDMonoClass *p_class);
+	static ManagedType from_class(MonoClass *p_mono_class);
+	static ManagedType from_type(MonoType *p_mono_type);
+	static ManagedType from_reftype(MonoReflectionType *p_mono_reftype);
+
+	ManagedType() :
+			type_encoding(0),
+			type_class(NULL) {
+	}
+
+	ManagedType(int p_type_encoding, GDMonoClass *p_type_class) :
+			type_encoding(p_type_encoding),
+			type_class(p_type_class) {
+	}
+};
+
+#endif // MANAGED_TYPE_H
diff --git a/modules/mono/signal_awaiter_utils.cpp b/modules/mono/signal_awaiter_utils.cpp
index 5051d83694..5d37e8212f 100644
--- a/modules/mono/signal_awaiter_utils.cpp
+++ b/modules/mono/signal_awaiter_utils.cpp
@@ -100,7 +100,7 @@ Variant SignalAwaiterHandle::_signal_callback(const Variant **p_args, int p_argc
 
 	MonoException *exc = NULL;
 	GD_MONO_BEGIN_RUNTIME_INVOKE;
-	invoke_method_thunk(CACHED_METHOD_THUNK(SignalAwaiter, SignalCallback), get_target(), signal_args, (MonoObject **)&exc);
+	invoke_method_thunk(CACHED_METHOD_THUNK(SignalAwaiter, SignalCallback), get_target(), signal_args, &exc);
 	GD_MONO_END_RUNTIME_INVOKE;
 
 	if (exc) {
@@ -132,7 +132,7 @@ SignalAwaiterHandle::~SignalAwaiterHandle() {
 		if (awaiter) {
 			MonoException *exc = NULL;
 			GD_MONO_BEGIN_RUNTIME_INVOKE;
-			invoke_method_thunk(CACHED_METHOD_THUNK(SignalAwaiter, FailureCallback), awaiter, (MonoObject **)&exc);
+			invoke_method_thunk(CACHED_METHOD_THUNK(SignalAwaiter, FailureCallback), awaiter, &exc);
 			GD_MONO_END_RUNTIME_INVOKE;
 
 			if (exc) {