fileno not visible when -std=c++11 is used

[Arthur Schwarz]

Win7 64-bit
gcc 4.8.2 (cygwin)

Ref:
http://stackoverflow.com/questions/14172884/no-fileno-function-in-nuwen-net-
mingw-distro

The 'fileno' function is not visible when -std=c++11 is used but is visible
when it is not. The reference indicates that this is a POSIX compliant
function which Mingw chooses to not implement because POSIX isn't Windows.
What is the position of the gcc group? Does 4.8.3 have fileno visible?

History: I have tried the flex C++ output but failed to achieve a successful
compile, and like the coward I am, when I discovered that the C output
compiled successfully I didn't pursue the issue further. But now I have a
need for using hexfloat in my input, works fine in output, in order to do
round-trip ASCII processing. Hexfloat is available in C++11 but unavailable
otherwise leading me to try to compile the flex output in C++11. 

Any help would be most appreciated.