NAME

std::basic_streambuf::showmanyc - std::basic_streambuf::showmanyc

Synopsis

protected:
virtual std::streamsize showmanyc();

Estimates the number of characters available for input in the associated character
sequence. underflow() is guaranteed not to return Traits::eof() or throw an
exception until at least that many characters are extracted.

Parameters

(none)

Return value

The number of characters that are certainly available in the associated character
sequence, or -1 if showmanyc can determine, without blocking, that no characters are
available. If showmanyc returns -1, underflow() and uflow() will definitely return
Traits::eof or throw.

The base class version returns 0, which has the meaning of "unsure if there
are characters available in the associated sequence".

Notes

The name of this function stands for "stream: how many characters?", so it is
pronounced "S how many C", rather than "show many C"

Example

This section is incomplete
Reason: no example

See also

in_avail obtains the number of characters immediately available in the get area
(public member function)
showmanyc optionally provides the number of characters available for input from the
[virtual] file
(virtual protected member function of std::basic_filebuf<CharT,Traits>)