In rust ! signifies invoking a macro, so it couldn't be used like this in a function name even if you wanted to. Also, Rust allows you to notate immutable/mutating/owning for each individual argument type, so there wouldn't be much point:

  fn do_thing(a_owned: Foo, b_mutating: &mut Foo, c_immutable: &Foo) {

There is a convention to separate the two kinds of functions (consume and return in some, mutate in others), but that's the only commonality