XkbKeyTypeIndex - Obtain the index of a key type or the pointer to a key type

-xkb  Xkb description of interest

       -keycode
              keycode of interest

       -group
              group index

XkbKeyTypeIndex  computes  an index into the types vector of the client map in xkb from the given keycode
       and group index.

X Version 11                                      libX11 1.7.5                                XkbKeyTypeIndex(3)

       XkbKeyTypeIndex - Obtain the index of a key type or the pointer to a key type

intXkbKeyTypeIndex(XkbDescPtrxkb,KeyCodekeycode,intgroup);