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

std::isblank(std::locale): std::isblank(std::locale)

NAME

std::isblank(std::locale) - std::isblank(std::locale)

Synopsis

Defined in header <locale>
template< class charT > (since C++11)
bool isblank( charT ch, const locale& loc );

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

Parameters

ch - character
loc - locale

Return value

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

Possible implementation

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

Example

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

  #include <iostream>
  #include <locale>

  void try_with(wchar_t c, const char* loc)
  {
      std::wcout << "isblank('" << c << "', locale(\"" << loc << "\")) returned " << std::boolalpha
                 << std::isblank(c, std::locale(loc)) << '\n';
  }
  int main()
  {
      const wchar_t IDEO_SPACE = L'\u3000'; // Unicode character 'IDEOGRAPHIC SPACE'
      try_with(IDEO_SPACE, "C");
      try_with(IDEO_SPACE, "en_US.UTF-8");
  }

Output:

  isblank(' ', locale("C")) returned false
  isblank(' ', locale("en_US.UTF-8")) returned true