update documentation on gotham_derive crate (#576)

gotham/src/state/data.rs

@@ -12,16 +12,12 @@ pub use gotham_derive::StateData;
 
 /// A marker trait for types that can be stored in `State`.
 ///
-/// This is typically implemented using `#[derive(StateData)]`, which is provided by the
-/// `gotham_derive` crate.
+/// This is typically implemented using `#[derive(StateData)]`.
 ///
 /// ```rust
-/// # extern crate gotham;
-/// # #[macro_use]
-/// # extern crate gotham_derive;
-/// #
 /// # use gotham::state::{FromState, State};
-/// #
+/// use gotham::state::StateData;
+///
 /// #[derive(StateData)]
 /// struct MyStateData {
 ///     x: u32,

gotham/src/state/mod.rs

@@ -47,23 +47,18 @@ impl Hasher for IdHasher {
 }
 
 /// Provides storage for request state, and stores one item of each type. The types used for
-/// storage must implement the `gotham::state::StateData` trait to allow its storage. The
-/// `gotham_derive` crate provides a custom derive for `StateData` to make this more convenient.
+/// storage must implement the [`StateData`] trait to allow its storage, which is usually done
+/// by adding `#[derive(StateData)]` on the type in question.
 ///
 /// # Examples
 ///
 /// ```rust
-/// extern crate gotham;
-/// #[macro_use]
-/// extern crate gotham_derive;
-///
-/// use gotham::state::State;
+/// use gotham::state::{State, StateData};
 ///
 /// #[derive(StateData)]
 /// struct MyStruct {
 ///     value: i32,
 /// }
-///
 /// # fn main() {
 /// #   State::with_new(|state| {
 /// #

gotham_derive/src/lib.rs

@@ -1,3 +1,6 @@
+//! This crate is a private implementation detail of `gotham`. You should never have to
+//! use this crate directly.
+
 mod extenders;
 mod new_middleware;
 mod state;

middleware/template/src/lib.rs

@@ -9,10 +9,6 @@
 #[macro_use]
 extern crate log;
 
-// Enable to use #[derive(StateData)] below
-//#[macro_use]
-//extern crate gotham_derive;
-
 use std::pin::Pin;
 
 use futures_util::future::{self, FutureExt, TryFutureExt};