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Defined in header <cwchar> | ||
std::wint_t ungetwc(std::wint_t ch,std::FILE* stream); | ||
Ifch does not equalWEOF, pushes the wide characterch into the input buffer associated with the streamstream in such a manner than subsequent read operation fromstream will retrieve that wide character. The external device associated with the stream is not modified.
Stream repositioning operationsstd::fseek,std::fsetpos, andstd::rewind discard the effects ofstd::ungetwc.
Ifstd::ungetwc is called more than once without an intervening read or repositioning, it may fail (in other words, a pushback buffer of size 1 is guaranteed, but any larger buffer is implementation-defined). If multiple successfulstd::ungetwc were performed, read operations retrieve the pushed-back wide characters in reverse order ofstd::ungetwc
Ifch equalsWEOF, the operation fails and the stream is not affected.
A successful call tostd::ungetwc clears the end of file status flagfeof.
A successful call tostd::ungetwc on a stream (whether text or binary) modifies the stream position indicator in unspecified manner but guarantees that after all pushed-back wide characters are retrieved with a read operation, the stream position indicator is equal to its value beforestd::ungetwc.
| ch | - | wide character to be put back |
| stream | - | file stream to put the wide character back to |
On successch is returned.
On failureWEOF is returned and the given stream remains unchanged.
| puts a character back into a file stream (function)[edit] | |
| gets a wide character from a file stream (function)[edit] | |
C documentation forungetwc | |
