std::ctype_byname(3)

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>
                        provides narrow character classification. This
   std::ctype_byname<char> 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 id of the locale
   [static] (public static member constant)
         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
   [static] (public static member constant)

Member functions
   is invokes do_is
                       (public member function of std::ctype<CharT>)
   scan_is invokes do_scan_is
                       (public member function of std::ctype<CharT>)
   scan_not invokes do_scan_not
                       (public member function of std::ctype<CharT>)
   toupper invokes do_toupper
                       (public member function of std::ctype<CharT>)
   tolower invokes do_tolower
                       (public member function of std::ctype<CharT>)
   widen invokes do_widen
                       (public member function of std::ctype<CharT>)
   narrow invokes do_narrow
                       (public member function of std::ctype<CharT>)
         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 obtains the "C" locale character classification table
   [static] (public static member function of std::ctype<char>)

Protected member functions
   do_toupper converts a character or characters to uppercase
   [virtual] (virtual protected member function of std::ctype<CharT>)
   do_tolower converts a character or characters to lowercase
   [virtual] (virtual protected member function of std::ctype<CharT>)
   do_widen converts a character or characters from char to charT
   [virtual] (virtual protected member function of std::ctype<CharT>)
   do_narrow converts a character or characters from charT to char
   [virtual] (virtual protected member function of std::ctype<CharT>)
         if CharT is char, the following members of std::ctype are NOT inherited
   do_is classifies a character or a character sequence
   [virtual] (virtual protected member function of std::ctype<CharT>)
   do_scan_is locates the first character in a sequence that conforms to given
   [virtual] classification
                (virtual protected member function of std::ctype<CharT>)
   do_scan_not locates the first character in a sequence that fails given
   [virtual] classification
                (virtual protected member function of std::ctype<CharT>) 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
   [static] (public static member constant)
   print the value of mask identifying printable character classification
   [static] (public static member constant)
   cntrl the value of mask identifying control character classification
   [static] (public static member constant)
   upper the value of mask identifying uppercase character classification
   [static] (public static member constant)
   lower the value of mask identifying lowercase character classification
   [static] (public static member constant)
   alpha the value of mask identifying alphabetic character classification
   [static] (public static member constant)
   digit the value of mask identifying digit character classification
   [static] (public static member constant)
   punct the value of mask identifying punctuation character classification
   [static] (public static member constant)
   xdigit the value of mask identifying hexadecimal digit character
   [static] classification
                    (public static member constant)
   blank the value of mask identifying blank character classification
   [static] (C++11) (public static member constant)
   alnum alpha | digit
   [static] (public static member constant)
   graph alnum | punct
   [static] (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
// 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

See also
   ctype defines character classification tables
               (class template)
   ctype<char> specialization of std::ctype for type char
               (class template specialization)