std::ctype_byname (3) - Linux Manuals

std::ctype_byname: std::ctype_byname

NAME

std::ctype_byname - std::ctype_byname

Synopsis

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

              constructs a new ctype_byname facet
constructor (public member function)
              destroys a ctype_byname facet
destructor (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 id of the locale
                                     (public static member constant)
[static]

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

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

Member functions

              invokes do_is
is (public member function of std::ctype<CharT>)
              invokes do_scan_is
scan_is (public member function of std::ctype<CharT>)
              invokes do_scan_not
scan_not (public member function of std::ctype<CharT>)
              invokes do_toupper
toupper (public member function of std::ctype<CharT>)
              invokes do_tolower
tolower (public member function of std::ctype<CharT>)
              invokes do_widen
widen (public member function of std::ctype<CharT>)
              invokes do_narrow
narrow (public member function of std::ctype<CharT>)

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

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

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

Protected member functions

do_toupper converts a character or characters to uppercase
            (virtual protected member function of std::ctype<CharT>)
[virtual]

do_tolower converts a character or characters to lowercase
            (virtual protected member function of std::ctype<CharT>)
[virtual]

do_widen converts a character or characters from char to charT
            (virtual protected member function of std::ctype<CharT>)
[virtual]

do_narrow converts a character or characters from charT to char
            (virtual protected member function of std::ctype<CharT>)
[virtual]

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

do_is classifies a character or a character sequence
            (virtual protected member function of std::ctype<CharT>)
[virtual]

do_scan_is locates the first character in a sequence that conforms to given classification
            (virtual protected member function of std::ctype<CharT>)
[virtual]

do_scan_not locates the first character in a sequence that fails given classification
            (virtual protected member function of std::ctype<CharT>)
[virtual]

Inherited from std::ctype_base

Member types

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

Member constants

space the value of mask identifying whitespace character classification
                 (public static member constant)
[static]

print the value of mask identifying printable character classification
                 (public static member constant)
[static]

cntrl the value of mask identifying control character classification
                 (public static member constant)
[static]

upper the value of mask identifying uppercase character classification
                 (public static member constant)
[static]

lower the value of mask identifying lowercase character classification
                 (public static member constant)
[static]

alpha the value of mask identifying alphabetic character classification
                 (public static member constant)
[static]

digit the value of mask identifying digit character classification
                 (public static member constant)
[static]

punct the value of mask identifying punctuation character classification
                 (public static member constant)
[static]

xdigit the value of mask identifying hexadecimal digit character classification
                 (public static member constant)
[static]

blank the value of mask identifying blank character classification
                 (public static member constant)
[static] (C++11)

alnum alpha | digit
                 (public static member constant)
[static]

graph alnum | punct
                 (public static member constant)
[static]

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

// Run this code

  #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