std::ctype<char>

 

C++

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Technical Specifications

 

Localizations library

Locales and facets
locale
use_facet	has_facet
Character classification
isspace isblank (C++11) iscntrl isupper islower isalpha	isdigit ispunct isxdigit isalnum isprint isgraph
Conversions
toupper tolower	wstring_convert (C++11) wbuffer_convert (C++11)
Facet category base classes
ctype_base codecvt_base messages_base	time_base money_base
Facet categories
ctype ctype<char> codecvt collate messages time_get time_put	num_get num_put numpunct money_get money_put moneypunct
Locale-specific facets
ctype_byname codecvt_byname messages_byname collate_byname	time_get_byname time_put_byname numpunct_byname moneypunct_byname
Code conversion facets
codecvt_utf8 (C++11) codecvt_utf16 (C++11)	codecvt_utf8_utf16 (C++11) codecvt_mode (C++11)
C locale
setlocale localeconv lconv	LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME

 

Defined in header <locale>
template<> class ctype<char>;

This specialization of std::ctype encapsulates character classification features for type char. Unlike general-purpose std::ctype, which uses virtual functions, this specialization uses table lookup to classify characters (which is generally faster).

The base class std::ctype<char> implements character classification equivalent to the minimal "C" locale. The classification rules can be extended or modified if constructed with a non-default classification table argument, if constructed as std::ctype_byname<char> or as a user-defined derived facet. All std::istream formatted input functions are required to use std::ctype<char> for character classing during input parsing.

Inheritance diagram

Member types

Member type	Definition
char_type	char

Member functions

(constructor)	constructs a new std::ctype<char> facet (public member function)
(destructor)	destructs a std::ctype<char> facet (protected member function)
table	obtains the character classification table (public member function)
classic_table [static]	obtains the "C" locale character classification table (public static member function)
is	classifies a character or a character sequence, using the classification table (public member function)
scan_is	locates the first character in a sequence that conforms to given classification, using the classification table (public member function)
scan_not	locates the first character in a sequence that fails given classification, using the classification table (public member function)
toupper	invokes do_toupper (public member function of std::ctype)
tolower	invokes do_tolower (public member function of std::ctype)
widen	invokes do_widen (public member function of std::ctype)
narrow	invokes do_narrow (public member function of std::ctype)

Protected member functions

do_toupper [virtual]	converts a character or characters to uppercase (virtual protected member function of std::ctype)
do_tolower [virtual]	converts a character or characters to lowercase (virtual protected member function of std::ctype)
do_widen [virtual]	converts a character or characters from char to charT (virtual protected member function of std::ctype)
do_narrow [virtual]	converts a character or characters from charT to char (virtual protected member function of std::ctype)

Member objects

static std::locale::id id [static]	id of the locale (public static member constant)
static const std::size_t table_size [static]	size of the classification table, at least 256 (public static member constant)

Inherited from std::ctype_base

Member types

Type	Definition
mask	unspecified bitmask type (enumeration, integer type, or bitset)

Member constants

space [static]	the value of mask identifying whitespace character classification (public static member constant)
print [static]	the value of mask identifying printable character classification (public static member constant)
cntrl [static]	the value of mask identifying control character classification (public static member constant)
upper [static]	the value of mask identifying uppercase character classification (public static member constant)
lower [static]	the value of mask identifying lowercase character classification (public static member constant)
alpha [static]	the value of mask identifying alphabetic character classification (public static member constant)
digit [static]	the value of mask identifying digit character classification (public static member constant)
punct [static]	the value of mask identifying punctuation character classification (public static member constant)
xdigit [static]	the value of mask identifying hexadecimal digit character classification (public static member constant)
blank [static] (C++11)	the value of mask identifying blank character classification (public static member constant)
alnum [static]	alpha | digit (public static member constant)
graph [static]	alnum | punct (public static member constant)