Add notes about enabling features to contrib docs.

contrib/lib/src/helmet/mod.rs

@@ -9,6 +9,18 @@
 //! [express]: https://expressjs.com
 //! [`SpaceHelmet`]: helmet::SpaceHelmet
 //!
+//! # Enabling
+//!
+//! This module is only available when the `helmet` feature is enabled. Enable
+//! it in `Cargo.toml` as follows:
+//!
+//! ```toml
+//! [dependencies.rocket_contrib]
+//! version = "0.4.0"
+//! default-features = false
+//! features = ["helmet"]
+//! ```
+//!
 //! # Supported Headers
 //!
 //! | HTTP Header                 | Description                            | Policy       | Default? |

contrib/lib/src/json.rs

@@ -1,6 +1,19 @@
 //! Automatic JSON (de)serialization support.
 //!
 //! See the [`Json`](json::Json) type for further details.
+//!
+//! # Enabling
+//!
+//! This module is only available when the `json` feature is enabled. Enable it
+//! in `Cargo.toml` as follows:
+//!
+//! ```toml
+//! [dependencies.rocket_contrib]
+//! version = "0.4.0"
+//! default-features = false
+//! features = ["json"]
+//! ```
+
 extern crate serde;
 extern crate serde_json;
 

contrib/lib/src/msgpack.rs

@@ -1,6 +1,18 @@
 //! Automatic MessagePack (de)serialization support.
 //!
 //! See the [`MsgPack`](msgpack::MessagePack) type for further details.
+//!
+//! # Enabling
+//!
+//! This module is only available when the `msgpack` feature is enabled. Enable
+//! it in `Cargo.toml` as follows:
+//!
+//! ```toml
+//! [dependencies.rocket_contrib]
+//! version = "0.4.0"
+//! default-features = false
+//! features = ["msgpack"]
+//! ```
 extern crate serde;
 extern crate rmp_serde;
 

contrib/lib/src/serve.rs

@@ -1,4 +1,18 @@
 //! Custom handler and options for static file serving.
+//!
+//! See the [`StaticFiles`](serve::StaticFiles) type for further details.
+//!
+//! # Enabling
+//!
+//! This module is only available when the `serve` feature is enabled. Enable it
+//! in `Cargo.toml` as follows:
+//!
+//! ```toml
+//! [dependencies.rocket_contrib]
+//! version = "0.4.0"
+//! default-features = false
+//! features = ["serve"]
+//! ```
 
 use std::path::{PathBuf, Path};
 

contrib/lib/src/uuid.rs

@@ -1,4 +1,18 @@
 //! UUID parameter and form value parsing support.
+//!
+//! See the [`Uuid`](uuid::Uuid) type for further details.
+//!
+//! # Enabling
+//!
+//! This module is only available when the `uuid` feature is enabled. Enable it
+//! in `Cargo.toml` as follows:
+//!
+//! ```toml
+//! [dependencies.rocket_contrib]
+//! version = "0.4.0"
+//! default-features = false
+//! features = ["uuid"]
+//! ```
 
 pub extern crate uuid as uuid_crate;
 

core/http/src/uri/from_uri_param.rs

@@ -75,12 +75,16 @@ use uri::{self, UriPart, UriDisplay};
 ///      `u32`, `u64`, `u128`, `usize`, `f32`, `f64`, `bool`, `IpAddr`,
 ///      `Ipv4Addr`, `Ipv6Addr`, `&str`, `&RawStr`, `Cow<str>`
 ///
-/// The following conversions are implemented:
+/// The following conversions are implemented, allowing a value of the type on
+/// the left to be used when a type on the right is expected by a route:
 ///
 ///   * `&str` to `String`
 ///   * `&str` to `RawStr`
 ///   * `String` to `&str`
 ///   * `String` to `RawStr`
+///   * `T` to `Option<T>`
+///   * `T` to `Result<T, E>`
+///   * `T` to `Form<T>`
 ///
 /// The following types have _identity_ implementations _only in [`Path`]_:
 ///
@@ -225,7 +229,7 @@ macro_rules! impl_conversion_ref {
     );
 }
 
-/// Macro to automatically generated _identity_ [`FromUriParam`] trait
+/// Macro to automatically generate _identity_ [`FromUriParam`] trait
 /// implementations.
 ///
 /// For a type `T`, the _identity_ implementations of `FromUriParam` are: