macro expansion of adding pin project to Request.req

macro-expansion-pin-project-request.rs

    pub struct Request<State> {
        pub(crate) state: State,
        pub(crate) req: http::Request,
        pub(crate) route_params: Vec<Params>,
    }

    #[allow(single_use_lifetimes)]
    #[allow(clippy::used_underscore_binding)]
    const _: () = {
        #[allow(dead_code)]
        #[allow(clippy::mut_mut)]
        #[allow(clippy::type_repetition_in_bounds)]
        pub(crate) struct Projection<'__pin, State>
        where
            Request<State>: '__pin,
        {
            pub(crate) state: &'__pin mut (State),
            pub(crate) req: ::pin_project_lite::__private::Pin<&'__pin mut (http::Request)>,
            pub(crate) route_params: &'__pin mut (Vec<Params>),
        }
        #[allow(dead_code)]
        #[allow(clippy::type_repetition_in_bounds)]
        pub(crate) struct ProjectionRef<'__pin, State>
        where
            Request<State>: '__pin,
        {
            pub(crate) state: &'__pin (State),
            pub(crate) req: ::pin_project_lite::__private::Pin<&'__pin (http::Request)>,
            pub(crate) route_params: &'__pin (Vec<Params>),
        }
        impl<State> Request<State> {
            pub(crate) fn project<'__pin>(
                self: ::pin_project_lite::__private::Pin<&'__pin mut Self>,
            ) -> Projection<'__pin, State> {
                unsafe {
                    let this = self.get_unchecked_mut();
                    Projection {
                        state: &mut this.state,
                        req: ::pin_project_lite::__private::Pin::new_unchecked(&mut this.req),
                        route_params: &mut this.route_params,
                    }
                }
            }
            pub(crate) fn project_ref<'__pin>(
                self: ::pin_project_lite::__private::Pin<&'__pin Self>,
            ) -> ProjectionRef<'__pin, State> {
                unsafe {
                    let this = self.get_ref();
                    ProjectionRef {
                        state: &this.state,
                        req: ::pin_project_lite::__private::Pin::new_unchecked(&this.req),
                        route_params: &this.route_params,
                    }
                }
            }
        }
        pub struct __Origin<'__pin, State> {
            __dummy_lifetime: ::pin_project_lite::__private::PhantomData<&'__pin ()>,
            state: ::pin_project_lite::__private::AlwaysUnpin<State>,
            req: http::Request,
            route_params: ::pin_project_lite::__private::AlwaysUnpin<Vec<Params>>,
        }
        impl<'__pin, State> ::pin_project_lite::__private::Unpin for Request<State> where
            __Origin<'__pin, State>: ::pin_project_lite::__private::Unpin
        {
        }
        trait MustNotImplDrop {}
        #[allow(clippy::drop_bounds)]
        impl<T: ::pin_project_lite::__private::Drop> MustNotImplDrop for T {}
        impl<State> MustNotImplDrop for Request<State> {}
        #[deny(safe_packed_borrows)]
        fn __assert_not_repr_packed<State>(this: &Request<State>) {
            &this.state;
            &this.req;
            &this.route_params;
        }
    };