NAME¶

std::basic_streambuf::in_avail - std::basic_streambuf::in_avail

Synopsis¶

std::streamsize in_avail();

Returns the number of characters available in the get area. If a read position is
available, effectively returns egptr() - gptr(), the size of the get area. In this
case, the number of bytes returned is the number of bytes that can be extracted from
the buffer without calling underflow().

If the get area is empty, calls showmanyc() to determine the number of bytes
available in the associated character sequence. In this case, the value returned is
the number of bytes that can be extracted from the buffer while it's guaranteed that
underflow() would not return Traits::eof.

Parameters¶

(none)

Return value¶

The number of characters available for non-blocking read (either the size of the get
area or the number of characters ready for reading from the associated character
sequence), or -1 if no characters are available in the associated sequence as far as
showmanyc() can tell.

Example¶

This section is incomplete
Reason: no example

See also¶

showmanyc optionally provides the number of characters available for input from the
[virtual] file
(virtual protected member function of std::basic_filebuf<CharT,Traits>)
readsome extracts already available blocks of characters
(public member function of std::basic_istream<CharT,Traits>)