ctype_base Class

The class serves as a base class for facets of template class ctype. A base class for the ctype class that is used to define enumeration types used to classify or test characters either individually or within entire ranges.

struct ctype_base : public locale::facet
{
    enum
    {
        alnum, alpha, cntrl, digit, graph,
        lower, print, punct, space, upper,
        xdigit
    };
    typedef short mask;
    ctype_base(
        size_t _Refs = 0
    );
    ~ctype_base();
};

Remarks

It defines an enumeration mask. Each enumeration constant characterizes a different way to classify characters, as defined by the functions with similar names declared in the header <ctype.h>. The constants are:

• space (function isspace)

• print (function isprint)

• cntrl (function iscntrl)

• upper (function isupper)

• lower (function islower)

• digit (function isdigit)

• punct (function ispunct)

• xdigit (function isxdigit)

• alpha (function isalpha)

• alnum (function isalnum)

• graph (function isgraph)

You can characterize a combination of classifications by ORing these constants. In particular, it is always true that alnum == (alpha | digit) and graph == (alnum | punct).

Requirements

Header: <locale>

Namespace: std

See Also

Reference

Thread Safety in the C++ Standard Library