Use 'diesel::r2d2' in state guide and todo example.

Diesel now reexports r2d2, so rather than including that library
explicitly, let's leverage the reexport.

examples/todo/Cargo.toml

@@ -9,10 +9,7 @@ rocket_codegen = { path = "../../codegen" }
 serde = "1.0"
 serde_json = "1.0"
 serde_derive = "1.0"
-r2d2 = "0.8"
-diesel = { version = "1.0", features = ["sqlite"] }
-diesel_derives = { version = "1.0", features = ["sqlite"] }
-r2d2-diesel = "1.0"
+diesel = { version = "1.0", features = ["sqlite", "r2d2"] }
 dotenv = "0.10"
 
 [dev-dependencies]

examples/todo/src/db.rs

@@ -1,23 +1,22 @@
 use std::ops::Deref;
 
-use r2d2;
 use diesel::sqlite::SqliteConnection;
-use r2d2_diesel::ConnectionManager;
+use diesel::r2d2::{ConnectionManager, Pool, PooledConnection};
 
 use rocket::http::Status;
 use rocket::request::{self, FromRequest};
 use rocket::{Request, State, Outcome};
 
-pub type Pool = r2d2::Pool<ConnectionManager<SqliteConnection>>;
+pub type SqlitePool = Pool<ConnectionManager<SqliteConnection>>;
 
 pub const DATABASE_URL: &'static str = env!("DATABASE_URL");
 
-pub fn init_pool() -> Pool {
+pub fn init_pool() -> SqlitePool {
     let manager = ConnectionManager::<SqliteConnection>::new(DATABASE_URL);
-    r2d2::Pool::new(manager).expect("db pool")
+    Pool::new(manager).expect("db pool")
 }
 
-pub struct Conn(pub r2d2::PooledConnection<ConnectionManager<SqliteConnection>>);
+pub struct Conn(pub PooledConnection<ConnectionManager<SqliteConnection>>);
 
 impl Deref for Conn {
     type Target = SqliteConnection;
@@ -32,7 +31,7 @@ impl<'a, 'r> FromRequest<'a, 'r> for Conn {
     type Error = ();
 
     fn from_request(request: &'a Request<'r>) -> request::Outcome<Conn, ()> {
-        let pool = request.guard::<State<Pool>>()?;
+        let pool = request.guard::<State<SqlitePool>>()?;
         match pool.get() {
             Ok(conn) => Outcome::Success(Conn(conn)),
             Err(_) => Outcome::Failure((Status::ServiceUnavailable, ()))

examples/todo/src/main.rs

@@ -3,11 +3,8 @@
 
 extern crate rocket;
 #[macro_use] extern crate diesel;
-#[macro_use] extern crate diesel_derives;
 #[macro_use] extern crate serde_derive;
 extern crate rocket_contrib;
-extern crate r2d2;
-extern crate r2d2_diesel;
 
 mod static_files;
 mod task;

site/guide/state.md

@@ -178,9 +178,8 @@ use the following dependencies:
 ```
 [dependencies]
 rocket = "0.4.0-dev"
-diesel = { version = "1.0", features = ["sqlite"] }
-r2d2-diesel = "1.0"
-r2d2 = "0.8"
+rocket_codegen = "0.4.0-dev"
+diesel = { version = "1.0", features = ["sqlite", "r2d2"] }
 ```
 
 Your `diesel` dependency information may differ. The crates are imported as
@@ -189,8 +188,6 @@ well:
 ```rust
 extern crate rocket;
 #[macro_use] extern crate diesel;
-extern crate r2d2_diesel;
-extern crate r2d2;
 ```
 
 ### Managed Pool
@@ -206,10 +203,10 @@ default configuration parameters and a Diesel `SqliteConnection`
 
 ```rust
 use diesel::sqlite::SqliteConnection;
-use r2d2_diesel::ConnectionManager;
+use diesel::r2d2::{ConnectionManager, Pool, PooledConnection};
 
 // An alias to the type for a pool of Diesel SQLite connections.
-type Pool = r2d2::Pool<ConnectionManager<SqliteConnection>>;
+type SqlitePool = Pool<ConnectionManager<SqliteConnection>>;
 
 // The URL to the database, set via the `DATABASE_URL` environment variable.
 static DATABASE_URL: &'static str = env!("DATABASE_URL");
@@ -217,7 +214,7 @@ static DATABASE_URL: &'static str = env!("DATABASE_URL");
 /// Initializes a database pool.
 fn init_pool() -> Pool {
     let manager = ConnectionManager::<SqliteConnection>::new(DATABASE_URL);
-    r2d2::Pool::new(manager).expect("db pool")
+    Pool::new(manager).expect("db pool")
 }
 ```
 
@@ -245,9 +242,10 @@ use std::ops::Deref;
 use rocket::http::Status;
 use rocket::request::{self, FromRequest};
 use rocket::{Request, State, Outcome};
+use diesel::r2d2::{ConnectionManager, Pool, PooledConnection};
 
 // Connection request guard type: a wrapper around an r2d2 pooled connection.
-pub struct DbConn(pub r2d2::PooledConnection<ConnectionManager<SqliteConnection>>);
+pub struct DbConn(pub PooledConnection<ConnectionManager<SqliteConnection>>);
 
 /// Attempts to retrieve a single connection from the managed database pool. If
 /// no pool is currently managed, fails with an `InternalServerError` status. If
@@ -255,8 +253,8 @@ pub struct DbConn(pub r2d2::PooledConnection<ConnectionManager<SqliteConnection>
 impl<'a, 'r> FromRequest<'a, 'r> for DbConn {
     type Error = ();
 
-    fn from_request(request: &'a Request<'r>) -> request::Outcome<DbConn, ()> {
-        let pool = request.guard::<State<Pool>>()?;
+    fn from_request(request: &'a Request<'r>) -> request::Outcome<Self, Self::Error> {
+        let pool = request.guard::<State<SqlitePool>>()?;
         match pool.get() {
             Ok(conn) => Outcome::Success(DbConn(conn)),
             Err(_) => Outcome::Failure((Status::ServiceUnavailable, ()))