I know SFML does not yet support multiple monitors, more than one fullscreen, etc. I was however, looking for a method to determine whether there was a second montior hooked up or not. I have no idea how to test in windows, but the only thing i can think of in linux is xrandr.
metulburr@laptop:~$ xrandr
Screen 0: minimum 8 x 8, current 3200 x 1080, maximum 8192 x 8192
VGA-0 disconnected (normal left inverted right x axis y axis)
TV-0 disconnected (normal left inverted right x axis y axis)
LVDS-0 connected 1280x800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
1280x800 60.0*+
HDMI-0 connected 1920x1080+1280+0 (normal left inverted right x axis y axis) 886mm x 498mm
1920x1080 60.0*+ 59.9 24.0 30.0 30.0
1440x480 30.0
1360x768 60.0
1360x765 60.0
1280x1024 60.0
1280x720 60.0 59.9
1024x768 60.0
800x600 60.3
720x480 59.9 30.0
640x480 59.9 59.9
metulburr@laptop:~$
Of course i am not exactly sure on how to parse the output in c++. Is there at least a method in SFML to test whether there is a lone monitor or not?