std::isupper(std::locale) (3) - Linux Manuals

std::isupper(std::locale): std::isupper(std::locale)


std::isupper(std::locale) - std::isupper(std::locale)


Defined in header <locale>
template< class charT >
bool isupper( charT ch, const locale& loc );

Checks if the given character is classified as an uppercase alphabetic character by the given locale's std::ctype facet.


ch - character
loc - locale

Return value

Returns true if the character is classified as uppercase, false otherwise.

Possible implementation

  template< class charT >
  bool isupper( charT ch, const std::locale& loc ) {
      return std::use_facet<std::ctype<charT>>(loc).is(std::ctype_base::upper, ch);


Demonstrates the use of isupper() with different locales (OS-specific).
// Run this code

  #include <iostream>
  #include <locale>
  int main()
      const wchar_t c = L'\u00de'; // capital letter thorn

      std::locale loc1("C");
      std::cout << "isupper('Þ', C locale) returned "
                 << std::boolalpha << std::isupper(c, loc1) << '\n';

      std::locale loc2("en_US.UTF8");
      std::cout << "isupper('Þ', Unicode locale) returned "
                << std::boolalpha << std::isupper(c, loc2) << '\n';


  isupper('Þ', C locale) returned false
  isupper('Þ', Unicode locale) returned true

See also

         checks if a character is an uppercase character
isupper (function)
         checks if a wide character is an uppercase character
iswupper (function)