std::numpunct::truename, do_truename, falsename, do_falsename - cppreference.com

##### cppreference.com

##### Search

Create account

##### Namespaces

- Page
- Discussion

##### Variants

##### Views

- View
- Edit
- History

##### Actions

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

From cppreference.com
< cpp‎ | locale‎ | numpunct

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

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.

### [edit] 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".

### [edit] 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;
        std::cout << "default locale: " << true << true << false << false << '\n';
        std::cout.imbue(std::locale(std::cout.getloc(), new custom_tf));
        std::cout << "locale with modified numpunct: "
                  << true << true << false << false << '\n';
    }

Output:

    default locale: truetruefalsefalse
    locale with modified numpunct: ttff

Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/locale/numpunct/truefalsename&oldid=89098"