ctype_base Class
The latest version of this topic can be found at 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.
Syntax
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