#include <wctype.h> int iswlower(wint_t wc);
The wide-character class "lower" is a subclass of the wide-character class "alpha", and therefore also a subclass of the wide-character class "alnum", of the wide-character class "graph" and of the wide-character class "print".
Being a subclass of the wide-character class "print", the wide-character class "lower" is disjoint from the wide-character class "cntrl".
Being a subclass of the wide-character class "graph", the wide-character class "lower" is disjoint from the wide-character class "space" and its subclass "blank".
Being a subclass of the wide-character class "alnum", the wide-character class "lower" is disjoint from the wide-character class "punct".
Being a subclass of the wide-character class "alpha", the wide-character class "lower" is disjoint from the wide-character class "digit".
The wide-character class "lower" contains at least those characters wc which are equal to towlower(wc) and different from towupper(wc).
The wide-character class "lower" always contains at least the letters 'a' to 'z'.
| Interface | Attribute | Value |
| iswlower() | Thread safety | MT-Safe locale |
This function is not very appropriate for dealing with Unicode characters, because Unicode knows about three cases: upper, lower, and title case.