NAME¶

std::toupper(std::locale) - std::toupper(std::locale)

Synopsis¶

Defined in header <locale>
template< class CharT >
CharT toupper( CharT ch, const locale& loc );

Converts the character ch to uppercase if possible, using the conversion rules
specified by the given locale's std::ctype facet.

Parameters¶

ch - character
loc - locale

Return value¶

Returns the uppercase form of ch if one is listed in the locale, otherwise returns
ch unchanged.

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::toupper.

Possible implementation¶

template<class CharT>
CharT toupper(CharT ch, const std::locale& loc)
{
return std::use_facet<std::ctype<CharT>>(loc).toupper(ch);
}

Example¶

// Run this code

#include <cwctype>
#include <iostream>
#include <locale>

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, toupper(" << (std::wint_t)c << ") = "
<< (std::wint_t)std::toupper(c, std::locale()) << '\n';

std::cout << "in Unicode locale, toupper(" << (std::wint_t)c << ") = "
<< (std::wint_t)std::toupper(c, std::locale("en_US.utf8")) << '\n';
}

Possible output:¶

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

See also¶

converts a character to lowercase using the ctype facet of a
tolower(std::locale) locale
(function template)
toupper converts a character to uppercase
(function)
towupper converts a wide character to uppercase
(function)