diff --git a/src/hb-iter.hh b/src/hb-iter.hh
index 02dd24099..8d72cbcd0 100644
--- a/src/hb-iter.hh
+++ b/src/hb-iter.hh
@@ -158,11 +158,11 @@ template<class T, typename B>
 struct _hb_is_iterable
 { enum { value = false }; };
 template<class T>
-struct _hb_is_iterable<T, hb_bool_tt<(bool) sizeof (hb_declval<T> ().iter ())> >
+struct _hb_is_iterable<T, hb_bool_tt<true || sizeof (hb_declval<T> ().iter ())> >
 { enum { value = true }; };
+
 template<class T>
 struct hb_is_iterable { enum { value = _hb_is_iterable<T, hb_true_t>::value }; };
-
 #define hb_is_iterable(Iterable) hb_is_iterable<Iterable>::value
 
 
diff --git a/src/hb-null.hh b/src/hb-null.hh
index cdd97d28d..4675c515f 100644
--- a/src/hb-null.hh
+++ b/src/hb-null.hh
@@ -50,7 +50,7 @@ template <typename T, typename B>
 struct _hb_null_size
 { enum { value = sizeof (T) }; };
 template <typename T>
-struct _hb_null_size<T, hb_bool_tt<(bool) (1 + (unsigned int) T::min_size)> >
+struct _hb_null_size<T, hb_bool_tt<true || sizeof (T::min_size)> >
 { enum { value = T::null_size }; };
 
 template <typename T>
@@ -67,7 +67,7 @@ template <typename T, typename B>
 struct _hb_static_size
 { enum { value = sizeof (T) }; };
 template <typename T>
-struct _hb_static_size<T, hb_bool_tt<(bool) (1 + (unsigned int) T::min_size)> >
+struct _hb_static_size<T, hb_bool_tt<true || sizeof (T::min_size)> >
 { enum { value = T::static_size }; };
 
 template <typename T>
@@ -84,10 +84,10 @@ template <typename T, typename V, typename B>
 struct _hb_assign
 { static inline void value (T &o, const V v) { o = v; } };
 template <typename T, typename V>
-struct _hb_assign<T, V, hb_bool_tt<(bool) (1 + (unsigned int) T::min_size)> >
+struct _hb_assign<T, V, hb_bool_tt<true || sizeof (T::min_size)> >
 { static inline void value (T &o, const V v) { o.set (v); } };
 template <typename T>
-struct _hb_assign<T, T, hb_bool_tt<(bool) (1 + (unsigned int) T::min_size)> >
+struct _hb_assign<T, T, hb_bool_tt<true || sizeof (T::min_size)> >
 { static inline void value (T &o, const T v) { o = v; } };
 
 template <typename T, typename V>