std::ctype_byname

Defined in header <locale>
template< class CharT > class ctype_byname : public std::ctype<CharT>;

std::ctype_byname is a std::ctype facet which encapsulates character classification rules of the locale specified at its construction.

Two specializations are provided by the standard library.

| Defined in header <locale> |

|:----|

| std::ctype_byname<char> | provides narrow character classification. This specialization uses table lookup for character classification |

| std::ctype_byname<wchar_t> | provides wide character classification |

Member types

Member type	Definition
mask	ctype<CharT>::mask

Member functions

(constructor)	constructs a new ctype_byname facet (public member function)
(destructor)	destroys a ctype_byname facet (protected member function)

std::ctype_byname::ctype_byname

explicit ctype_byname( const char* name, std::size_t refs = 0 );
explicit ctype_byname( const std::string& name, std::size_t refs = 0 );		(since C++11)

Constructs a new std::ctype_byname facet for a locale with name.

refs is used for resource management: if refs == 0, the implementation destroys the facet, when the last std::locale object holding it is destroyed. Otherwise, the object is not destroyed.

Parameters

name	-	the name of the locale
refs	-	the number of references that link to the facet

std::ctype_byname::~ctype_byname

protected: ~ctype_byname();

Destroys the facet.

Inherited from std::ctype<CharT>

Member types

Member type	Definition
char_type	CharT

Member objects

Member name	Type
static std::locale::id id static	id of the locale (public static member constant)

| if CharT is char, the following member of std::ctype<char> is inherited |

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

Member functions

is	invokes do_is (public member function of std::ctype)
scan_is	invokes do_scan_is (public member function of std::ctype)
scan_not	invokes do_scan_not (public member function of std::ctype)
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)

| if CharT is char, the following members of std::ctype<char> are inherited |

| table | obtains the character classification table (public member function of std::ctype<char>) |

| classic_table static | obtains the "C" locale character classification table (public static member function of std::ctype<char>) |

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)

| if CharT is char, the following members of std::ctype are NOT inherited |

| do_is virtual | classifies a character or a character sequence (virtual protected member function of std::ctype) |

| do_scan_is virtual | locates the first character in a sequence that conforms to given classification (virtual protected member function of std::ctype) |

| do_scan_not virtual | locates the first character in a sequence that fails given classification (virtual protected member function of std::ctype) |

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	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)

Notes

The explicit specialization std::ctype_byname<char> was listed as a separate entry in the header file <locale> until C++11. it was removed in C++11 as defect #1298, but it remains a required specialization, just like std::ctype_byname<wchar_t>.

Example

#include <iostream>
#include <locale>
 
int main()
{
    wchar_t c = L'\u00de'; // capital letter thorn
 
    std::locale loc("C");
 
    std::cout << "isupper('Þ', C locale) returned "
               << std::boolalpha << std::isupper(c, loc) << '\n';
 
    loc = std::locale(loc, new std::ctype_byname<wchar_t>("en_US.utf8"));
 
    std::cout << "isupper('Þ', C locale with Unicode ctype) returned "
              << std::boolalpha << std::isupper(c, loc) << '\n';
}

Output:

isupper('Þ', C locale) returned false
isupper('Þ', C locale with Unicode ctype) returned true

Member types

Member functions

std::ctype_byname::ctype_byname

Parameters

std::ctype_byname::~ctype_byname

Inherited from std::ctype<CharT>

Member types

Member objects

Member functions

Protected member functions

Inherited from std::ctype_base

Member types

Member constants

Notes

Example

See also