Infer generic argument based on function arguments

[hellow554]

Since veryl is heavily inspired by rust, I would like to have the following code to work without any hints to the transpiler:

struct Source2<WIDTH: const> {
    which: logic,
    value: logic <WIDTH>,
}

function decode_source2::<WIDTH: const> (
        inp: input logic<WIDTH + 1>,
    ) -> Source2::<WIDTH> {
        return {
            inp[msb],
            inp[msb - 1:0],
        };
    }

Currently I have to write decode_source2::<16>(ir[16:0]), but I would like to be able to write decode_source2(ir[16:0]) since the WIDTH const argument can be deduced.

I know, that this can be a very hard problem to solve, but maybe at one day the transpiler can get this functionality <3