diff -r d375d8056262 -r 878a450e79bd src/cx/array_list.h
--- a/src/cx/array_list.h	Tue Sep 17 23:11:17 2024 +0200
+++ b/src/cx/array_list.h	Tue Sep 17 23:19:03 2024 +0200
@@ -300,6 +300,7 @@
  *
  * In other words, this function returns the index of the largest element
  * in \p arr that is less or equal to \p elem with respect to \p cmp_func.
+ * When no such element exists, \p size is returned.
  *
  * If \p elem is contained in the array, this is identical to
  * #cx_array_binary_search().
@@ -312,7 +313,7 @@
  * @param elem_size the size of one element
  * @param elem the element to find
  * @param cmp_func the compare function
- * @return the index of the closest element in the array
+ * @return the index of the largest upper bound, or \p size
  */
 size_t cx_array_binary_search_inf(
         void const *arr,