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

std::iscntrl(std::locale): std::iscntrl(std::locale)

NAME

std::iscntrl(std::locale) - std::iscntrl(std::locale)

Synopsis

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

Checks if the given character is classified as a control character by the given locale's std::ctype facet.

Parameters

ch - character
loc - locale

Return value

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

Possible implementation

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

Example

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

  #include <iostream>
  #include <locale>
  int main()
  {
      const wchar_t CCH = L'\u0094'; // Destructive Backspace in Unicode

      std::locale loc1("C");
      std::cout << "iscntrl(CCH, C locale) returned "
                << std::boolalpha << std::iscntrl(CCH, loc1) << '\n';

      std::locale loc2("en_US.UTF8");
      std::cout << "iscntrl(CCH, Unicode locale) returned "
                << std::boolalpha << std::iscntrl(CCH, loc2) << '\n';
  }

Output:

  iscntrl(CCH, C locale) returned false
  iscntrl(CCH, Unicode locale) returned true