std:: mbrtoc8

From cppreference.com
Defined in header <cuchar>
std:: size_t mbrtoc8 ( char8_t * pc8,

const char * s,
std:: size_t n,

std:: mbstate_t * ps ) ;
(since C++20)

Converts a narrow multibyte character to UTF-8 encoding.

If s is not a null pointer, inspects at most n bytes of the multibyte character string, beginning with the byte pointed to by s to determine the number of bytes necessary to complete the next multibyte character (including any shift sequences). If the function determines that the next multibyte character in s is complete and valid, converts it to UTF-8 and stores the first UTF-8 code unit in * pc8 (if pc8 is not null).

If UTF-8 encoding of the multibyte character in * s consists of more than one UTF-8 code unit, then after the first call to this function, * ps is updated in such a way that the next call to mbrtoc8 will write out the additional UTF-8 code units, without considering * s .

If s is a null pointer, the values of n and pc8 are ignored and the call is equivalent to std :: mbrtoc8 ( nullptr, "" , 1 , ps ) .

If UTF-8 code unit produced is u8 ' \0 ' , the conversion state * ps represents the initial shift state.

The multibyte encoding used by this function is specified by the currently active C locale.

Parameters

pc8 - pointer to the location where the resulting UTF-8 code units will be written
s - pointer to the multibyte character string used as input
n - limit on the number of bytes in s that can be examined
ps - pointer to the conversion state object used when interpreting the multibyte string

Return value

The first of the following that applies:

  • 0 if the character converted from s (and stored in * pc8 if non-null) was the null character.
  • the number of bytes [ 1 ... n ] of the multibyte character successfully converted from s .
  • static_cast < std:: size_t > ( - 3 ) if the next UTF-8 code unit from a character whose encoding consists of multiple code units has now been written to * pc8 . No bytes are processed from the input in this case.
  • static_cast < std:: size_t > ( - 2 ) if the next n bytes constitute an incomplete, but so far valid, multibyte character. Nothing is written to * pc8 .
  • static_cast < std:: size_t > ( - 1 ) if encoding error occurs. Nothing is written to * pc8 , the value EILSEQ is stored in errno and the value of * ps is unspecified.

Example

See also

(C++20)
converts UTF-8 string to narrow multibyte encoding
(function)
(C++11)
converts a narrow multibyte character to UTF-16 encoding
(function)
C documentation for mbrtoc8