Find the position of the first bit set in mask, searching
from (but not including) nth_bit downwards. Bits are numbered
from 0 (least significant) to sizeof(gulong) * 8 - 1 (31 or 63,
usually). To start searching from the last bit, set nth_bit to
-1 or GLIB_SIZEOF_LONG * 8.
Parameters
mask: number
a gulong containing flags
nth_bit: number
the index of the bit to start the search from
Returns number
the index of the first bit set which is lower than nth_bit, or -1 if no lower bits are set
Find the position of the first bit set in
mask, searching from (but not including)nth_bitdownwards. Bits are numbered from 0 (least significant) to sizeof(gulong) * 8 - 1 (31 or 63, usually). To start searching from the last bit, setnth_bitto -1 or GLIB_SIZEOF_LONG * 8.