Standard C++ Library Reference ISO/IEC (VERSION3)

iswgraph
int iswgraph(wint_t c);
The function returns nonzero if c is any character for which either iswalnum or iswpunct
returns nonzero.
iswlower
int iswlower(wint_t c);
The function returns nonzero if c is any of:
a b c d e f g h i j k l m n o p q r s t u v w x y z
or any other locale-specific lowercase character.
iswprint
int iswprint(wint_t c);
The function returns nonzero if c is space, a character for which iswgraph returns nonzero,
or an implementation-defined subset of the characters for which iswspace returns nonzero.
iswpunct
int iswpunct(wint_t c);
The function returns nonzero if c is any of:
! " # % & ' ( ) ; <
= > ? [ \ ] * + , -
. / : ^ _ { | } ~
or any other implementation-defined punctuation character.
iswspace
int iswspace(wint_t c);
The function returns nonzero if c is any of:
CR FF HT NL VT space
or any other locale-specific space character.