- * This returns false if we run out of memory, or (more normally) if that
- * string already appears in the set.
+ * This returns false if we run out of memory (errno = ENOMEM), or
+ * (more normally) if that string already appears in the set (EEXIST).
*
* Note that the pointer is placed in the set, the string is not copied. If
* you want a copy in the set, use strdup().
*
* Note that the pointer is placed in the set, the string is not copied. If
* you want a copy in the set, use strdup().
- * This returns the string which was passed to strset_set(), or NULL.
+ * This returns the string which was passed to strset_set(), or NULL if
+ * the string was not in the map (in which case it sets errno = ENOENT).
+ *