XkbFreeGeomOverlayKeys - Man Page
Free keys in an overlay row
void XkbFreeGeomOverlayKeys (XkbRowPtr row, int first, int count, Bool free_all);
row in which keys should be freed
first key to be freed
number of keys to be freed
True => all keys are freed
Xkb provides a number of functions to allocate and free subcomponents of a keyboard geometry. Use these functions to create or modify keyboard geometries. Note that these functions merely allocate space for the new element(s), and it is up to you to fill in the values explicitly in your code. These allocation functions increase sz_* but never touch num_* (unless there is an allocation failure, in which case they reset both sz_* and num_* to zero). These functions return Success if they succeed, BadAlloc if they are not able to allocate space, or BadValue if a parameter is not as expected.
If free_all is True, all keys are freed regardless of the value of first and count. Otherwise, the number of keys specified by count are freed, beginning with the key specified by first in the specified row.
The XkbFreeGeomOverlayKeys function returns Success if there are no allocation or argument errors.
Unable to allocate storage
An argument is out of range