C++ In a Nutshell

Name

wcsrtombs function — Converts a wide string to a multibyte string

Synopsis

size_t wcsrtombs(char* dst, const wchar_t** src, size_t len, mbstate_t* ps)

The wcsrtombs function converts a wide string to a string of multibyte characters. The src parameter points indirectly to the source wide string, that is, *src points to the start of the wide string.

If dst is not null, up to len bytes are stored in dst. If fewer than len bytes are stored, a trailing null character is appended to the narrow character array. If conversion stops upon reaching a null wide character in the src string, a null pointer is assigned to *src; otherwise, *src is assigned a pointer to the character immediately past the end of the last wide character converted.

The dst parameter can be null, in which case no narrow characters are stored and *src is not altered, but ps is updated and the return value is the same as it would be if dst were large enough to hold the entire converted string.

The ps parameter points to the shift state, which keeps track of the conversion state between calls to wcsrtombs. If ps is null, an internal shift state is used (which is similar to calling wcstombs in <cstdlib>). If the conversion ends without a terminating null character in *src, the shift state is reset to an mbstate_t initial state.

If any of the wide characters cannot be represented as a multibyte character, static_cast<size_t>(-1) is returned. Otherwise, the return value is the number of bytes successfully converted from wide ...