24 Strings library [strings]

24.5 Null-terminated sequence utilities [c.strings]

24.5.2 Header <cwctype> synopsis [cwctype.syn]

namespace std {
  using wint_t = see below;
  using wctrans_t = see below;
  using wctype_t = see below;

  int iswalnum(wint_t wc);
  int iswalpha(wint_t wc);
  int iswblank(wint_t wc);
  int iswcntrl(wint_t wc);
  int iswdigit(wint_t wc);
  int iswgraph(wint_t wc);
  int iswlower(wint_t wc);
  int iswprint(wint_t wc);
  int iswpunct(wint_t wc);
  int iswspace(wint_t wc);
  int iswupper(wint_t wc);
  int iswxdigit(wint_t wc);
  int iswctype(wint_t wc, wctype_t desc);
  wctype_t wctype(const char* property);
  wint_t towlower(wint_t wc);
  wint_t towupper(wint_t wc);
  wint_t towctrans(wint_t wc, wctrans_t desc);
  wctrans_t wctrans(const char* property);

#define WEOF see below
The contents and meaning of the header <cwctype> are the same as the C standard library header <wctype.h>.
See also: ISO C 7.30