diff --git a/TODO b/TODO
index 74a85e0c3..421deff1a 100644
--- a/TODO
+++ b/TODO
@@ -33,3 +33,4 @@ TODO:
 * doc: IMPLICIT_DIR_DOCS for dir docs or \dir
 * meta non-const allow_cast overloads: (const int &) to (int &) is not allowed, but (const int &) to (double &) is allowed (support only for convertibles)
 * improve non-const allow cast with in-place switch
+* meta fixed_size could return the size directly if present