std::iswcntrl

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Technical Specifications

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Functions
Character manipulation
iswalnum iswalpha iswlower iswupper iswdigit iswxdigit iswblank (C++11) wctype iswctype	iswcntrl iswgraph iswspace iswprint iswpunct towlower towupper wctrans towctrans
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wcstolwcstoll (C++11) wcstoulwcstoull (C++11)	wcstofwcstodwcstold (C++11)(C++11) wcstoimaxwcstouimax (C++11)(C++11)
String manipulation
wcslen wcscpy wcsncpy wcscat wcsncat wcscmp wcscoll wcsncmp	wcsxfrm wcschr wcsrchr wcspbrk wcsspn wcscspn wcsstr wcstok
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Defined in header <cwctype>
int iswcntrl( std::wint_t ch );

Checks if the given wide character is a control character, i.e. codes 0x00-0x1F and 0x7F and any control characters specific to the current locale.

If the value of ch is neither representable as a wchar_t nor equal to the value of the macro WEOF, the behavior is undefined.

Parameters

ch

-

wide character

Return value

Non-zero value if the wide character is a control character, zero otherwise.

Notes

ISO 30112 defines POSIX control characters as Unicode characters U+0000..U+001F, U+007F..U+009F, U+2028, and U+2029 (Unicode classes Cc, Zl, and Zp)

Example

Run this code

#include <iostream>
#include <cwctype>
#include <clocale>

int main()
{
    wchar_t c = L'\u2028'; // the Unicode character "line separator" 

    std::cout << std::hex << std::showbase << std::boolalpha;
    std::cout << "in the default locale, iswcntrl(" << (std::wint_t)c << ") = "
              << (bool)std::iswcntrl(c) << '\n';
    std::setlocale(LC_ALL, "en_US.utf8");
    std::cout << "in Unicode locale, iswcntrl(" << (std::wint_t)c << ") = "
              << (bool)std::iswcntrl(c) << '\n';
}

Output:

in the default locale, iswcntrl(0x2028) = false
in Unicode locale, iswcntrl(0x2028) = true

See also

iscntrl(std::locale)	checks if a character is classified as a control character by a locale (function template)
iscntrl	checks if a character is a control character (function)

ASCII values			characters	iscntrl iswcntrl	isprint iswprint	isspace iswspace	isblank iswblank	isgraph iswgraph	ispunct iswpunct	isalnum iswalnum	isalpha iswalpha	isupper iswupper	islower iswlower	isdigit iswdigit	isxdigit iswxdigit
decimal	hexadecimal	octal
08	\x0\x8	\0\10	control codes (NUL, etc.)	0	0	0	0	0	0	0	0	0	0	0	0
9	\x9	\11	tab (\t)	0	0	0	0	0	0	0	0	0	0	0	0
1013	\xA\xD	\12\15	whitespaces (\n, \v, \f, \r)	0	0	0	0	0	0	0	0	0	0	0	0
1431	\xE\x1F	\16\37	control codes	0	0	0	0	0	0	0	0	0	0	0	0
32	\x20	\40	space	0	0	0	0	0	0	0	0	0	0	0	0
3347	\x21\x2F	\41\57	!"#$%&'()*+,-./	0	0	0	0	0	0	0	0	0	0	0	0
4857	\x30\x39	\60\71	0123456789	0	0	0	0	0	0	0	0	0	0	0	0
5864	\x3A\x40	\72\100	:;<=>?@	0	0	0	0	0	0	0	0	0	0	0	0
6570	\x41\x46	\101\106	ABCDEF	0	0	0	0	0	0	0	0	0	0	0	0
7190	\x47\x5A	\107\132	GHIJKLMNOP QRSTUVWXYZ	0	0	0	0	0	0	0	0	0	0	0	0
9196	\x5B\x60	\133\140	[\]^_`	0	0	0	0	0	0	0	0	0	0	0	0
97102	\x61\x66	\141\146	abcdef	0	0	0	0	0	0	0	0	0	0	0	0
103122	\x67\x7A	\147\172	ghijklmnop qrstuvwxyz	0	0	0	0	0	0	0	0	0	0	0	0
123126	\x7B\x7E	\172\176	{|}~	0	0	0	0	0	0	0	0	0	0	0	0
127	\x7F	\177	backspace character (DEL)	0	0	0	0	0	0	0	0	0	0	0	0