Namespaces
Variants
Views
Actions

std::mbrtoc16

From cppreference.com
< cpp‎ | string‎ | multibyte
Revision as of 12:10, 10 September 2012 by P12 (Talk | contribs)

Defined in header <cuchar>
std::size_t mbrtoc16( char16_t* pc16,

                      const char* s,
                      std::size_t n,

                      std::mbstate_t* ps );
(since C++11)

Converts a narrow multibyte character to 16-bit character representation (typically, UTF-16).

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 the corresponding 16-bit character and stores it in *pc16 (if pc16 is not null).

If the multibyte character in *s corresponds to a multi-char16_t sequence (e.g. a surrogate pair in UTF-16), then after the first call to this function, *ps is updated in such a way that the next call to mbrtoc16 will write out the additional char16_t, without considering *s.

If s is a null pointer, the values of n and pc16 are ignored and the call is equivalent to std::mbrtoc16(NULL, "", 1, ps).

If the wide character produced is the null character, the conversion state *ps represents the initial shift state.

If the macro __STDC_UTF_16__ is defined, the 16-bit encoding used by this function is UTF-16, otherwise it is implementation-defined.

Parameters

pc16 - pointer to the location where the resulting 16-bit character 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 *pc16 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 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.
  • static_cast<std::size_t>(-2) if the next n bytes constitute an incomplete, but so far valid, multibyte character. Nothing is written to *pc16.
  • static_cast<std::size_t>(-1) if encoding error occurs. Nothing is written to *pc16, the value EILSEQ is stored in errno and the value if *ps is unspecified.

See also

Template:cpp/string/multibyte/dcl list c16rtombTemplate:cpp/locale/codecvt/dcl list do in
C documentation for mbrtoc16