# std::ctype_byname<char>

From cppreference.com
< cpp‎ | locale

Defined in header `<locale>` |  |
template<> class ctype_byname : public std::ctype<char>; |  |

This specialization of std::ctype_byname encapsulates character classification features for type char. Like its base class `std::ctype<char>` and unlike general-purpose std::ctype_byname, table lookup is used to classify characters

### Member types

Member type | Definition
`mask` | `ctype<char>::mask`

### Member functions

(constructor) | constructs a new ctype_byname<char> facet (public member function)
(destructor) | destructs a ctype_byname<char> facet (protected member function)

## Inherited from std::ctype<char>

### Member types

Member type | Definition
`char_type` | `char`

### Member objects

Member name | Type
`id` (static) | std::locale::id
`table_size` (static const) | std::size_t size of the classification table, at least 256

### Member functions

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>`)
is | classifies a character or a character sequence, using the classification table (public member function of `std::ctype<char>`)
scan_is | locates the first character in a sequence that conforms to given classification, using the classification table (public member function of `std::ctype<char>`)
scan_not | locates the first character in a sequence that fails given classification, using the classification table (public member function of `std::ctype<char>`)
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>`)

### Protected member functions

do_toupper [virtual] | converts a character or characters to uppercase (virtual protected member function of `std::ctype<CharT>`)
do_tolower [virtual] | converts a character or characters to lowercase (virtual protected member function of `std::ctype<CharT>`)
do_widen [virtual] | converts a character or characters from char to `CharT` (virtual protected member function of `std::ctype<CharT>`)
do_narrow [virtual] | converts a character or characters from `CharT` to char (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 [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] (C++11) | 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)

### Example

Run this code

    #include <iostream>
    #include <locale>

    int main()
    {
        char c = '\xde'; // 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<char>("en_US.utf8"));

        std::cout << "isupper('Þ', C locale with Unicode ctype<char>) returned "
                  << std::boolalpha << std::isupper(c, loc) << '\n';

        loc = std::locale(loc, new std::ctype_byname<char>("is_IS.iso88591"));

        std::cout << "isupper('Þ', C locale with Islandic ctype<char>) returned "
                  << std::boolalpha << std::isupper(c, loc) << '\n';
    }

Output:

    isupper('Þ', C locale) returned false
    isupper('Þ', C locale with Unicode ctype<char>) returned false
    isupper('Þ', C locale with Islandic ctype<char>) 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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