glib:variant-type-next (vtype)

vtype -- a g:variant-type instance from a previous call

The next g:variant-type instance after type, or nil.

Determines the next item type of a tuple or dictionary entry type. The vtype argument must be the result of a previous call to the g:variant-type-first or g:variant-type-next functions. If called on the key type of a dictionary entry then this call returns the value type. If called on the value type of a dictionary entry then this call returns nil. For tuples, nil is returned when vtype is the last item in a tuple.