The mbrtoc32() is a built-in function in C/C++ which converts a narrow multibyte character to a 32 bit character representation. It is defined within the uchar.h header file of C++.
size_t mbrtoc32( char32_t* pc32, 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.
- pc32 : specifies to the memory location to store the resulting 32 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 32 bit character.
- -3 if the next char16_t from a multi-char32_t character (e.g. a surrogate pair) has now been written to *pc32. 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 *pc32.
- -1 if encoding error occurs. In this case nothing is written to *pc32, errno is set to EILSEQ and the value of *ps is unspecified.
Below programs illustrate the above function.
Multibyte string = S Length = 1 32-bit character = 0x0053
Multibyte string = S Length = 1 32-bit character = 0x00000053