Function bitmap_to_port_list 

pub fn bitmap_to_port_list(
    bitmap: &BitVec<u8, Msb0>,
    ingress_port: u16,
    radix: u16,
) -> Vec<u16>

Collect output ports from a bitmap, excluding the ingress port.

Bits at or above radix are ignored, which means that a bitmap cannot address a port outside the pipeline.

The bitmap is interpreted as a little-endian integer: bit N (i.e., the bit with numeric value 2^N) corresponds to port N. This matches the encoding used by P4 arithmetic (128w1 << port) via bitmath::shl_le.