std::iswspace

int iswspace( wint_t ch );

Checks if the given wide character is a wide whitespace character as classified by the currently installed C locale. In the default locale, the whitespace characters are the following:

• Space (0x20, ' ')
• Form feed (0x0c, '\f')
• Line feed (0x0a, '\n')
• Carriage return (0x0d, '\r')
• Horizontal tab (0x09, '\t')
• Vertical tab (0x0b, '\v').

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

Return value

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

Notes

ISO 30112 defines POSIX space characters as Unicode characters U+0009..U+000D, U+0020, U+1680, U+180E, U+2000..U+2006, U+2008..U+200A, U+2028, U+2029, U+205F, and U+3000.

Example

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

void try_with(wchar_t c, const char* loc)
{
    std::setlocale(LC_ALL, loc);
    std::wcout << "isspace('" << c << "') in " << loc << " locale returned "
               << std::boolalpha << static_cast<bool>(std::iswspace(c)) << '\n';
}

int main()
{
    const wchar_t EM_SPACE = L'\u2003'; // Unicode character 'EM SPACE'
    try_with(EM_SPACE, "C");
    try_with(EM_SPACE, "en_US.UTF8");
}

isspace(' ') in C locale returned false
isspace(' ') in en_US.UTF8 locale returned true

See also