diff --git a/CMakeLists.txt b/CMakeLists.txt
index 357e7b2..1af5676 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,6 +21,7 @@ add_executable(${PROJECT_NAME}
 	src/collisionline.d
 	src/rect.d
 	src/collidingentity.d
+	src/objref.d
 
 	lib/DerelictSDL2/source/derelict/sdl2/functions.d
 	lib/DerelictSDL2/source/derelict/sdl2/image.d
diff --git a/src/collisionline.d b/src/collisionline.d
index 8c46911..3954073 100644
--- a/src/collisionline.d
+++ b/src/collisionline.d
@@ -18,11 +18,12 @@
 module collisionline;
 public import vector : Vector;
 import rect : Rect;
+import objref;
 
 alias vec2 = Vector!(float, 2);
 
 struct CollisionLine {
-	this (in vec2 parA, in vec2 parB) {
+	this (vec2 parA, vec2 parB) {
 		m_from = parA;
 		m_to = parB;
 		assert(m_from != m_to);
@@ -55,11 +56,15 @@ struct CollisionQuad {
 	alias m_lines this;
 }
 
-bool collides (CollisionLine parLine, CollisionLine parLine1, vec2 parOffs, out vec2 parPoint) {
+alias CollisionQuadRef = TObjRef!(const(CollisionQuad)).ObjRef;
+alias CollisionLineRef = TObjRef!(const(CollisionLine)).ObjRef;
+alias vec2ref = TObjRef!(const(vec2)).ObjRef;
+
+bool collides (CollisionLineRef parLine, CollisionLineRef parLine1, vec2ref parOffs, out vec2 parPoint) {
 	parPoint = vec2(0.0f);
 	return false;
 }
 
-bool collides (CollisionQuad parQuad, CollisionQuad parQuad1, vec2 parOffs, out vec2 parPoint) {
+bool collides (CollisionQuadRef parQuad, CollisionQuadRef parQuad1, vec2ref parOffs, out vec2 parPoint) {
 	return false;
 }
diff --git a/src/objref.d b/src/objref.d
new file mode 100644
index 0000000..7e86dd8
--- /dev/null
+++ b/src/objref.d
@@ -0,0 +1,36 @@
+/* Copyright 2015, Michele Santullo
+ * This file is part of "Jumping in D".
+ *
+ * "Jumping in D" 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.
+ *
+ * "Jumping in D" 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 "Jumping in D".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+module objref;
+
+template TObjRef(T) {
+	static if (T.sizeof > size_t.sizeof) {
+		struct ObjRef {
+			this(ref T parMainObj) {
+				m_ref = &parMainObj;
+			}
+
+			ref inout(T) get_ref() inout { return *m_ref; }
+			alias get_ref this;
+
+			private T* m_ref;
+		}
+	}
+	else {
+		alias ObjRef = T;
+	}
+}