[shove70]

1. Fixed Unkown type error when inferring type from params struct with a generic embedded struct. #20030
2. Add tests.

pub type Handler[T] = fn (mut T) bool

@[params]
pub struct Options[T] {
	handler fn (mut T) bool @[required]
}

struct Collector[T] {
mut:
	handlers []Handler[T]
}

pub fn (mut c Collector[T]) use(options Options[T]) {
	c.handlers << options.handler
}

pub struct Context {}

fn test_handler(mut ctx Context) bool {
	println('from test_handler!')
	return true
}

pub struct MainStruct {
	Collector[Context]
}

fn main() {
	mut s := MainStruct{}
	s.use(handler: test_handler)
	assert s.handlers.len == 1
}

outputs:

passed

[spytheman]

Excellent work.