table of contents
std::basic_streambuf::showmanyc(3) | C++ Standard Libary | std::basic_streambuf::showmanyc(3) |
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>)
2022.07.31 | http://cppreference.com |