Wcrtomb Function In Cc++

The wcrtomb function in C/C++ converts a wide character into its corresponding narrow multibyte forms. It takes a wide-character wc, converts it into its multibyte equivalents, and stores them in the array pointed to by s. This function also indicates the byte length of the resulting multibyte sequence stored in s.

Syntax:

It has the following Syntax:

size_t wcrtomb( char* st, wchar_t wcl, mbstate_t* pss )

Parameters: The function requires three necessary arguments, which are listed below:

• ✅ st: It provides the reference to an array large enough to store a multibyte sequence.
• ✅ wcl: It indicates the wide characters to convert.
• ✅ pss: It define the conversion state used while reading the multibyte text.

Return values: The function provides the following outcomes:

• ✅ In case of success, it delivers the count of bytes moved to the character array pointed to by st.
• ✅ If unsuccessful, it yields -1 and updates errno to EILSEQ.

The wcrtombs function converts a wide character, beginning in the provided conversion state saved in mbstate, from the numeric value in wcl to the position indicated by mbchar. The pReturnValue variable will indicate the total number of bytes converted, up to a maximum of MBCUR_MAX bytes, or -1 in case of an error.

If the mbstate is devoid of content, the internal conversion condition of mbstate_t is employed. In scenarios where a solitary character within wcl lacks a corresponding multibyte character, the pReturnValue will be set to -1, triggering the method to yield the EILSEQ errno outcome.

Example:

// C++ Program to implement the 
// wcrtomb() function in c++
#include <bits/stdc++.h> 
using namespace std; 

int main() 
{ 
	setlocale(LC_ALL, "en_US.utf8"); 

	// string initialization
	wchar_t wcl[] = L"z\u00df\u6c34\U0001f34c"; 

	// array for storing the values
	char st[25]; 
	int returnValue; 

	// state
	mbstate_t pss= mbstate_t(); 
	for (int i = 0; i < wcslen(wcl); i++) { 
		returnValue = wcrtomb(st, wcl[i], &pss); 

		// display of the pointer size
		if (returnValue != -1) 
			cout << "Size of " << st << " is "
				<< returnValue << " bytes" << endl; 
		else
			cout << "Invalid wide character" << endl; 
	} 

	return 0; 
}

Output:

Size of zU is 1 bytes
Invalid wide character
Invalid wide character
Invalid wide character