Block which has vectors of different sizes as input and output


I am still a beginner in GNU Radio. I created a block which receives as
a parameter a vector of integers, and the output is a vector with size
equal to the length of the parameter vector. I was trying to use it in

This is the important part of the xml file:

select input v_idx (411, 820) int_vector


out complex *****LENGTH($v_idx)*****

So, I don’t know how to tell GRC to get the size of the output vector
from the length of v_idx.

I would like to know if it is possible to solve this without using an
additional parameter specifying the length of v_idx.