wcsrtombs() function in C/C++

The wcsrtombs() function converts wide character to multibyte string. This function converts the wide character string represented by *src to corresponding multibyte character string and is stored in the character array pointed to by dest if dest is not null. A maximum of len characters are written to dest.
Syntax: 

size_t wcsrtombs( char* dest, const wchar_t** src, size_t len, mbstate_t* ps )

Parameters: The function accepts four mandatory parameters which are described below: 

• dest : Pointer to an array of char elements long enough to store a string of max bytes
• src : Pointer to a wide string to be translated
• len : Maximum number of bytes available in dest array
• ps : Pointer to the conversion state object

Return value : The function returns two value as below: 

• On success it returns the number of bytes written to dest(not including the eventual terminating null character)
• If some error occurs then -1 is returned and errno is set to EILSEQ.

Below programs illustrate the above function: 
Program 1: 

CPP

// C++ program to illustrate
// wcsrtombs() function
#include <bits/stdc++.h>
using namespace std;

int main()
{

    // initialize the string
    const wchar_t* src = L"Geekforgeeks";

    // maximum length of the dest
    char dest[20];

    // initial state
    mbstate_t ps = mbstate_t();

    // maximum length of multibyte character
    int len = 12;

    // function to convert wide-character
    // to multibyte string
    int value = wcsrtombs(dest, &src, len, &ps);

    cout << "Number of multibyte characters = " << value << endl;

    cout << "Multibyte characters written = " << dest << endl;

    return 0;
}

Output:

Number of multibyte characters = 12
Multibyte characters written = Geekforgeeks

Program 2: 

CPP

// C++ program to illustrate
// wcsrtombs() function
#include <bits/stdc++.h>
using namespace std;

int main()
{

    // initialize the string
    const wchar_t* src = L"This website is the best";

    // maximum length of the dest
    char dest[20];

    // initial state
    mbstate_t ps = mbstate_t();

    // maximum length of multibyte character
    int len = 14;

    // function to convert wide-character
    // to multibyte string
    int value = wcsrtombs(dest, &src, len, &ps);

    cout << "Number of multibyte characters = " << value << endl;

    cout << "Multibyte characters written = " << dest << endl;

    return 0;
}

Output:

Number of multibyte characters = 14
Multibyte characters written = This website i