I have been testing Xbox game streaming in Windows 10. When streaming a game, the Xbox app only supports controllers(gamepads). Would it be possible to map both the mouse and keyboard to the controller to essentially trick the Xbox program into thinking a controller is being used when it would be keyboard & mouse?
You probably could if you wanted to cheat at FPS / TPS titles using xpadder or similar to emulate an Xbox One controller from KB+M. I know there are programs to emulate mouse as analog for emulating console FPS like the Metroid Prime trilogy, Goldeneye, Perfect Dark, etc.
Note that this IS cheating, because mouse+keyboard DEMOLISH controllers (PC Master Race!) in Games Where You Shoot Guns (tm) AND you even keep the auto-aim that makes controllers almost-sort-of-usable. If you do pull off an emulated controller to use your KB+M in Master Chief Collection / Halo 5 and Microsoft finds out, you might get a Live suspension.
ED: Upvoted the question, because I want to go on a rampage through Halo MCC with mouse aiming and put it on YouTube now.
I haven't test it out myself yet, but theoretically you might be able to use a program like xpadder to map the keyboard to the controller buttons. It works for a lot of emulators and games that don't natively support an xbox controller.
I wrote a plugin for FreePIE with a dependency on SCPSever that allows you to emulate output as an Xbox controller. Technically you could write a script that would allow you to use a keyboard and mouse (or another joystick). The plugin hasn't really been very well tested, and I wasn't quite sure what I was doing too much when writing the code, but it seemed to work for basic examples.
Feel free to contribute to it if you find any issues.