Enable and fix several more clippy lints.

lib/entity/src/lib.rs

@@ -30,9 +30,20 @@
 //!   `Vec`.
 
 #![deny(missing_docs, trivial_numeric_casts, unused_extern_crates)]
+#![warn(unused_import_braces, unstable_features)]
 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
 #![cfg_attr(feature = "cargo-clippy",
-            allow(new_without_default, new_without_default_derive, redundant_field_names))]
+            allow(new_without_default, new_without_default_derive))]
+#![cfg_attr(feature="cargo-clippy", warn(
+                float_arithmetic,
+                mut_mut,
+                nonminimal_bool,
+                option_map_unwrap_or,
+                option_map_unwrap_or_else,
+                print_stdout,
+                unicode_not_nfc,
+                use_self,
+                ))]
 
 // Turns on no_std and alloc features if std is not available.
 #![cfg_attr(not(feature = "std"), no_std)]
@@ -91,7 +102,7 @@ macro_rules! entity_impl {
 
         impl $crate::__core::fmt::Display for $entity {
             fn fmt(&self, f: &mut $crate::__core::fmt::Formatter) -> $crate::__core::fmt::Result {
-                write!(f, "{}{}", $display_prefix, self.0)
+                write!(f, concat!($display_prefix, "{}"), self.0)
             }
         }