C++ IOS::widen() function

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The C++ std::ios::widen() function is used to convert a character to its wide character equivalent in the streams associated locale. It is mainly used when working with internationalization, where characters may need to be represented in a wide format for proper handling.

widen() is a member function of the std::ios_base class used in conjunction with input/output operations.

Syntax

Following is the syntax for std::ios::widen() function.

char widen (char c) const;

Parameters

• c − It indicates the character to be widened.

Return Value

It returns the wide equivalent of c.

Exceptions

If an exception is thrown, there are no changes in the stream.

Data races

Accesses the stream object.

Concurrent access to the same stream object may cause data races.

Example

In the following example, we are going to consider the basic usage of the widen() function.

#include <iostream>
#include <locale>
int main()
{
    std::cout << std::cout.widen('A') << std::endl;
    return 0;
}

Output

Output of the above code is as follows −

A

Example

Consider the following example, where we are going to convert a string to wide character.

#include <iostream>
#include <locale>
#include <string>
#include <vector>
int main()
{
    std::ios a(nullptr);
    std::string b = "TutorialsPoint";
    std::vector<wchar_t> x;
    for (char c : b) {
        x.push_back(a.widen(c));
    }
    for (wchar_t wc : x) {
        std::wcout << wc << " ";
    }
    return 0;
}

Output

Following is the output of the above code −

T u t o r i a l s P o i n t