| filebuf::pbackfail | virtual protected member |
int pbackfail ( int c = EOF ); |
Put character back on backup underflow
If the parameter c is EOF and the get pointer is not at the beginning of the character sequence, the get pointer is decreased by one.
If the parameter c is a value other than EOF and the get pointer is not at the beginning of the character sequence, c replaces the character at the putback position in the controlled input sequence. This character replacement only happens in the internal controlled input sequence and affects the values returned by at least the next input operation, but the contents of the file are not modified because of this operation.
This member function overrides the virtual member streambuf::pbackfail, which is called by other member functions of streambuf.
Parameters
- c
- Character to be put back, or EOF (or traits::eof() for other traits) to keep the existing character at that position.
Return Value
The function returns EOF (or traits::eof() for other traits) if it failed and therefore the get pointer was not modified.A value different from EOF (or traits::eof() for other traits) is returned to indicate success. If c was specified, the value returned on success is c.
Basic template member declaration
( basic_filebuf<charT,traits,Allocator> )
typedef traits::int_type int_type;
int_type pbackfail ( int_type c = traits::eof() );
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See also
| filebuf::underflow | Get character in the case of underflow (virtual protected member function) |