use std::ops::Deref;

struct M;

impl M {
  fn foo(&self) {
    println!("Called foo on M");
  }
}

struct S {
  m: M
}

impl Deref for S {
  type Target = M;
  fn deref<'a>(&'a self) -> &'a Self::Target {
    &self.m
  }
}

fn main() {
  let s = S { m: M };
  s.foo();
}