std::towupper

std::wint_t towupper( std::wint_t ch );

Converts the given wide character to uppercase, if possible.

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

Uppercase version of ch or unmodified ch if no uppercase version is listed in the current C locale.

Notes

Only 1:1 character mapping can be performed by this function, e.g. the uppercase form of 'ß' is (with some exceptions) the two-character string "SS", which cannot be obtained by std::towupper.

ISO 30112 specifies which pairs of Unicode characters are included in this mapping.

Example

#include <iostream>
#include <cwctype>
#include <clocale>
 
int main()
{
    wchar_t c = L'\u017f'; // Latin small letter Long S ('ſ')
 
    std::cout << std::hex << std::showbase;
    std::cout << "in the default locale, towupper(" << (std::wint_t)c << ") = "
              << std::towupper(c) << '\n';
    std::setlocale(LC_ALL, "en_US.utf8");
    std::cout << "in Unicode locale, towupper(" << (std::wint_t)c << ") = "
              << std::towupper(c) << '\n';
}

in the default locale, towupper(0x17f) = 0x17f
in Unicode locale, towupper(0x17f) = 0x53

See also