Update clippy settings and fix a few clippy warnings.

lib/entity/src/lib.rs

@@ -15,9 +15,9 @@
 //!
 //! - [`PrimaryMap`](struct.PrimaryMap.html) is used to keep track of a vector of entities,
 //!   assigning a unique entity reference to each.
-//! - [`SecondaryMap`](struct.SecondaryMap.html) is used to associate secondary information to an entity.
-//!   The map is implemented as a simple vector, so it does not keep track of which entities have
-//!   been inserted. Instead, any unknown entities map to the default value.
+//! - [`SecondaryMap`](struct.SecondaryMap.html) is used to associate secondary information to an
+//!   entity. The map is implemented as a simple vector, so it does not keep track of which
+//!   entities have been inserted. Instead, any unknown entities map to the default value.
 //! - [`SparseMap`](struct.SparseMap.html) is used to associate secondary information to a small
 //!   number of entities. It tracks accurately which entities have been inserted. This is a
 //!   specialized data structure which can use a lot of memory, so read the documentation before
@@ -35,7 +35,7 @@
 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
 #![cfg_attr(
     feature = "cargo-clippy",
-    allow(new_without_default, new_without_default_derive)
+    allow(clippy::new_without_default, clippy::new_without_default_derive)
 )]
 #![cfg_attr(
     feature = "cargo-clippy",

lib/entity/src/map.rs

@@ -11,8 +11,8 @@ use std::vec::Vec;
 /// A mapping `K -> V` for densely indexed entity references.
 ///
 /// The `SecondaryMap` data structure uses the dense index space to implement a map with a vector.
-/// Unlike `PrimaryMap`, an `SecondaryMap` can't be used to allocate entity references. It is used to
-/// associate secondary information with entities.
+/// Unlike `PrimaryMap`, an `SecondaryMap` can't be used to allocate entity references. It is used
+/// to associate secondary information with entities.
 ///
 /// The map does not track if an entry for a key has been inserted or not. Instead it behaves as if
 /// all keys have a default entry from the beginning.

lib/entity/src/sparse.rs

@@ -37,19 +37,20 @@ pub trait SparseMapValue<K> {
 ///
 /// # Compared to `SecondaryMap`
 ///
-/// When should we use a `SparseMap` instead of a secondary `SecondaryMap`? First of all, `SparseMap`
-/// does not provide the functionality of a `PrimaryMap` which can allocate and assign entity
-/// references to objects as they are pushed onto the map. It is only the secondary entity maps
-/// that can be replaced with a `SparseMap`.
+/// When should we use a `SparseMap` instead of a secondary `SecondaryMap`? First of all,
+/// `SparseMap` does not provide the functionality of a `PrimaryMap` which can allocate and assign
+/// entity references to objects as they are pushed onto the map. It is only the secondary entity
+/// maps that can be replaced with a `SparseMap`.
 ///
 /// - A secondary entity map assigns a default mapping to all keys. It doesn't distinguish between
 ///   an unmapped key and one that maps to the default value. `SparseMap` does not require
 ///   `Default` values, and it tracks accurately if a key has been mapped or not.
-/// - Iterating over the contents of an `SecondaryMap` is linear in the size of the *key space*, while
-///   iterating over a `SparseMap` is linear in the number of elements in the mapping. This is an
-///   advantage precisely when the mapping is sparse.
-/// - `SparseMap::clear()` is constant time and super-fast. `SecondaryMap::clear()` is linear in the
-///   size of the key space. (Or, rather the required `resize()` call following the `clear()` is).
+/// - Iterating over the contents of an `SecondaryMap` is linear in the size of the *key space*,
+///   while iterating over a `SparseMap` is linear in the number of elements in the mapping. This
+///   is an advantage precisely when the mapping is sparse.
+/// - `SparseMap::clear()` is constant time and super-fast. `SecondaryMap::clear()` is linear in
+///   the size of the key space. (Or, rather the required `resize()` call following the `clear()`
+///   is).
 /// - `SparseMap` requires the values to implement `SparseMapValue<K>` which means that they must
 ///   contain their own key.
 pub struct SparseMap<K, V>