std::ctype_byname(3) | C++ Standard Libary | 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)
2022.07.31 | http://cppreference.com |