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std:: isblank (std::locale)

From cppreference.net
C++
Text processing library
Localization library
Defined in header <locale>
template < class CharT >
bool isblank ( CharT ch, const locale & loc ) ;
(since C++11)

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

Contents

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");
}

Possible output: 

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

See also

(C++11)
checks if a character is a blank character
(function)
(C++11)
checks if a wide character is a blank character
(function)