Fix clippy issues, resolve tech debt (#60)

* fix clippy issue

* remove compat.rs file

Use alloc crate dependencies directly instead.

* update criterion

Cargo.toml

@@ -20,7 +20,7 @@ serde = { version = "1.0", default-features = false, features = ["alloc"], optio
 
 [dev-dependencies]
 serde_json = "1.0"
-criterion = "0.3"
+criterion = "0.5.1"
 fxhash = "0.2"
 
 [[bench]]

src/backend/bucket/mod.rs

@@ -5,10 +5,12 @@ mod interned_str;
 
 use self::{fixed_str::FixedString, interned_str::InternedStr};
 use super::Backend;
-use crate::{compat::Vec, symbol::expect_valid_symbol, DefaultSymbol, Symbol};
+use crate::{symbol::expect_valid_symbol, DefaultSymbol, Symbol};
 #[cfg(not(feature = "std"))]
 use alloc::string::String;
+use alloc::vec::Vec;
 use core::{iter::Enumerate, marker::PhantomData, slice};
+
 /// An interner backend that reduces memory allocations by using string buckets.
 ///
 /// # Note

src/backend/buffer.rs

@@ -1,7 +1,8 @@
 #![cfg(feature = "backends")]
 
 use super::Backend;
-use crate::{compat::Vec, symbol::expect_valid_symbol, DefaultSymbol, Symbol};
+use crate::{symbol::expect_valid_symbol, DefaultSymbol, Symbol};
+use alloc::vec::Vec;
 use core::{marker::PhantomData, mem, str};
 
 /// An interner backend that appends all interned string information in a single buffer.

src/backend/simple.rs

@@ -1,12 +1,8 @@
 #![cfg(feature = "backends")]
 
 use super::Backend;
-use crate::{
-    compat::{Box, ToString, Vec},
-    symbol::expect_valid_symbol,
-    DefaultSymbol,
-    Symbol,
-};
+use crate::{symbol::expect_valid_symbol, DefaultSymbol, Symbol};
+use alloc::{boxed::Box, string::ToString, vec::Vec};
 use core::{iter::Enumerate, marker::PhantomData, slice};
 
 /// A simple backend that stores a separate allocation for every interned string.

src/backend/string.rs

@@ -1,12 +1,8 @@
 #![cfg(feature = "backends")]
 
 use super::Backend;
-use crate::{
-    compat::{String, Vec},
-    symbol::expect_valid_symbol,
-    DefaultSymbol,
-    Symbol,
-};
+use crate::{symbol::expect_valid_symbol, DefaultSymbol, Symbol};
+use alloc::{string::String, vec::Vec};
 use core::{iter::Enumerate, marker::PhantomData, slice};
 
 /// An interner backend that accumulates all interned string contents into one string.

src/interner.rs

@@ -1,16 +1,11 @@
-use crate::{
-    backend::Backend,
-    compat::{DefaultHashBuilder, HashMap},
-    DefaultBackend,
-    DefaultSymbol,
-    Symbol,
-};
+use crate::{backend::Backend, DefaultBackend, DefaultSymbol, Symbol};
 use core::{
     fmt,
     fmt::{Debug, Formatter},
     hash::{BuildHasher, Hash, Hasher},
     iter::FromIterator,
 };
+use hashbrown::{hash_map::DefaultHashBuilder, HashMap};
 
 /// Creates the `u64` hash value for the given value using the given hash builder.
 fn make_hash<T>(builder: &impl BuildHasher, value: &T) -> u64
@@ -215,7 +210,7 @@ where
             //         we receive from our backend making them valid.
             string == unsafe { backend.resolve_unchecked(*symbol) }
         });
-        use crate::compat::hash_map::RawEntryMut;
+        use hashbrown::hash_map::RawEntryMut;
         let (&mut symbol, &mut ()) = match entry {
             RawEntryMut::Occupied(occupied) => occupied.into_key_value(),
             RawEntryMut::Vacant(vacant) => {

src/lib.rs

@@ -122,20 +122,23 @@
 //! Never use this one for real use cases!
 
 #[cfg(not(feature = "std"))]
+#[macro_use]
 extern crate alloc;
+#[cfg(feature = "std")]
+extern crate std as alloc;
 
 #[cfg(feature = "serde-1")]
 mod serde_impl;
 
 pub mod backend;
-mod compat;
 mod interner;
 pub mod symbol;
 
 #[doc(inline)]
 pub use self::{
     backend::DefaultBackend,
-    compat::DefaultHashBuilder,
     interner::StringInterner,
     symbol::{DefaultSymbol, Symbol},
 };
+#[doc(inline)]
+pub use hashbrown::hash_map::DefaultHashBuilder;