This is needed as the in and out endpoint are defined as follows:
static const uint8_t epInterruptInIndex = 1; // InterruptIN endpoint index
static const uint8_t epInterruptOutIndex = 2; // InterruptOUT endpoint index
And maxEpPerInterface is set to 2.
See: https://travis-ci.org/felis/USB_Host_Shield_2.0/jobs/569260660
The following collisions resolved:
hid.h -> usbhid.h
hid.cpp -> usbhid.cpp
HID -> USBHID
HID_BOOT_PROTOCOL -> USB_HID_BOOT_PROTOCOL
HID_PROTOCOL_NONE -> USB_HID_PROTOCOL_NONE
HID_PROTOCOL_KEYBOARD -> USB_HID_PROTOCOL_KEYBOARD
HID_PROTOCOL_MOUSE -> USB_HID_PROTOCOL_MOUSE
As a result, it's possible to use the library together with Arduino's bundled HID / Mouse / Keyboard libraries (Leonardo, Micro, or Due).
https://www.arduino.cc/en/Reference/MouseKeyboard