mbrtoc16() in C/C++ with Examples
The mbrtoc16() is a built-in function in C/C++ which converts a narrow multibyte character to a 16 bit character representation. It is defined within the uchar.h header file of C++.
Syntax:
ssize_t mbrtoc16( char16_t* pc16, const char* s, size_t n, mbstate_t* ps);
Parameters: The function accepts four mandatory parameter which are described below:
- s : specifies to the multibyte character to convert.
- pc16 : specifies to the memory location to store the resulting 16 bit character.
- n : specifies the maximum number of bytes in s to convert.
- ps : specifies to an mbstate_t object used when interpreting the multibyte string.
Return Value: The function returns five values as follows:
- 0 if the converted character is a null character.
- the number of bytes (at most n) of the multibyte character that was successfully converted to 16 bit character.
- -3 if the next char16_t from a multi-char16_t character (e.g. a surrogate pair) has now been written to *pc16. No bytes are processed from the input in this case.
- -2 if the next n bytes constitute an incomplete, but so far valid, multibyte character. In this case nothing is written to *pc16.
- -1 if encoding error occurs. In this case nothing is written to *pc16, errno is set to EILSEQ and the value of *ps is unspecified.
Below programs illustrate the above function.
Program 1:
// C++ program to illustrate the // mbrtoc16() function #include <cstdio> #include <cstdlib> #include <iostream> #include <uchar.h> #include <wchar.h> using namespace std; int main( void ) { char16_t pc16; char s[] = "G" ; mbstate_t ps{}; int length; // initializing the function length = mbrtoc16(&pc16, s, MB_CUR_MAX, &ps); if (length < 0) { perror ( "mbrtoc16() fails to convert" ); exit (-1); } cout << "Multibyte string = " << s << endl; cout << "Length = " << length << endl; printf ( "16-bit character = 0g%02hd\n" , pc16); } |
Output:
Multibyte string = G Length = 1 16-bit character = 0g71
Program 2:
// C++ program to illustrate the // mbrtoc16() function #include <cstdio> #include <cstdlib> #include <iostream> #include <uchar.h> #include <wchar.h> using namespace std; int main( void ) { char16_t pc16; char s[] = "" ; mbstate_t ps{}; int length; // initializing the function length = mbrtoc16(&pc16, s, MB_CUR_MAX, &ps); if (length < 0) { perror ( "mbrtoc16() fails to convert" ); exit (-1); } cout << "Multibyte string = " << s << endl; cout << "Length = " << length << endl; printf ( "16-bit character = 1e%04xy\n" , pc16); } |
Output:
Multibyte string = Length = 0 16-bit character = 1e0000y