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std::numpunct::truename,do_truename,falsename,do_falsename(3) C++ Standard Libary std::numpunct::truename,do_truename,falsename,do_falsename(3)

NAME

std::numpunct::truename,do_truename,falsename,do_falsename - std::numpunct::truename,do_truename,falsename,do_falsename

Synopsis


Defined in header <locale>
public: (1)
string_type truename() const;
public: (2)
string_type falsename() const;
protected: (3)
virtual string_type do_truename() const;
protected: (4)
virtual string_type do_falsename() const;


1-2) Public member function, calls the member function do_truename and do_falsename
of the most derived class respectively.
3) Returns the string to be used as the representation of the boolean value true.
4) Returns the string to be used as the representation of the boolean value false.

Return value


1,3) The object of type string_type to use as the representation of true. The
standard specializations of std::numpunct return "true" and L"true".
2,4) The object of type string_type to use as the representation of false. The
standard specializations of std::numpunct return "false" and L"false".

Example

// Run this code


#include <iostream>
#include <locale>
#include <iomanip>


struct custom_tf : std::numpunct<char> {
std::string do_truename() const { return "t"; }
std::string do_falsename() const { return "f"; }
};


int main()
{
std::cout << std::boolalpha;


// default boolalpha output
std::cout << "Default locale," << '\n'
<< " boolalpha true: " << true << '\n'
<< " boolalpha false: " << false << "\n\n";


// with custom_tf applied to locale
std::cout.imbue(std::locale(std::cout.getloc(), new custom_tf));
std::cout << "Locale with modified numpunct," << '\n'
<< " boolalpha true: " << true << '\n'
<< " boolalpha false: " << false << '\n';
}

Output:


Default locale,
boolalpha true: true
boolalpha false: false


Locale with modified numpunct,
boolalpha true: t
boolalpha false: f

2022.07.31 http://cppreference.com