std::ctype_byname
std::ctype_byname
| Defined in header | | |
|---|---|---|
| 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
See also
| ctype | defines character classification tables (class template) |
|---|---|
| ctype<char> | specialization of std::ctype for type char (class template specialization) |
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