use std::marker::PhantomPinned; use auxiliary_macro::add_pin_attr; use pin_project::pin_project; #[pin_project] #[add_pin_attr(struct)] //~ ERROR duplicate #[pin] attribute struct Foo { #[pin] f: PhantomPinned, } #[add_pin_attr(struct)] //~ ERROR #[pin] attribute may only be used on fields of structs or variants #[pin_project] struct Bar { #[pin] f: PhantomPinned, } fn main() {}