Can't get the middleware example to work

[beowulf1416]

I copied the example from the page https://actix.rs/docs/middleware/ about creating a middleware but I cannot get it to work. The Service trait requires 1 generics argument but 2 generics argument is being passed.

[robjtede]

I suspect you're using the v4 beta which uses a slightly tweaked Service trait. See docs for it here: https://docs.rs/actix-service/2.0.1/actix_service/trait.Service.html. Also read the build-in middleware for some extra guidance: https://github.com/actix/actix-web/tree/master/src/middleware.