avoid using parking_lot now that we have bumped the MSRV

Cargo.toml

@@ -25,7 +25,6 @@ maintenance = { status = "actively-developed" }
 
 [dependencies]
 
-parking_lot = "0.12.1"
 ahash = { version = "0.8.5", optional = true }
 dashmap = { version = "5.4.0", optional = true }
 once_cell = { version = "1.4", optional = true }

src/arena.rs

@@ -1,8 +1,8 @@
 #![deny(missing_docs)]
 use crate::boxedset::HashSet;
-use parking_lot::Mutex;
 use std::borrow::Borrow;
 use std::hash::{Hash, Hasher};
+use std::sync::Mutex;
 
 /// A arena for storing interned data
 ///
@@ -71,7 +71,7 @@ impl<T: Eq + Hash> Arena<T> {
     /// allocate a spot for the value on the heap.  Otherwise, it will return a
     /// pointer to the object previously allocated.
     pub fn intern(&self, val: T) -> ArenaIntern<T> {
-        let mut m = self.data.lock();
+        let mut m = self.data.lock().unwrap();
         if let Some(b) = m.get(&val) {
             let p = b.as_ref() as *const T;
             return ArenaIntern {
@@ -94,7 +94,7 @@ impl<T: Eq + Hash + ?Sized> Arena<T> {
         Box<T>: From<&'b I>,
         I: Eq + std::hash::Hash + ?Sized,
     {
-        let mut m = self.data.lock();
+        let mut m = self.data.lock().unwrap();
         if let Some(b) = m.get(val) {
             let p = b.as_ref() as *const T;
             return ArenaIntern {
@@ -113,7 +113,7 @@ impl<T: Eq + Hash + ?Sized> Arena<T> {
         Box<T>: From<I>,
         I: Eq + std::hash::Hash + AsRef<T>,
     {
-        let mut m = self.data.lock();
+        let mut m = self.data.lock().unwrap();
         if let Some(b) = m.get(val.as_ref()) {
             let p = b.as_ref() as *const T;
             return ArenaIntern {
@@ -346,7 +346,7 @@ impl<T: Eq + Hash + ?Sized> Arena<T> {
         T: 'a + Borrow<I> + From<&'b I>,
         I: Eq + std::hash::Hash + ?Sized,
     {
-        let mut m = self.data.lock();
+        let mut m = self.data.lock().unwrap();
         if let Some(b) = m.get(val) {
             let p = b.as_ref() as *const T;
             return ArenaIntern {

src/container.rs

@@ -1,7 +1,7 @@
-use parking_lot::Mutex;
 use std::any::Any;
 use std::any::TypeId;
 use std::hash::{Hash, Hasher};
+use std::sync::Mutex;
 
 pub struct TypeHolderSend(Vec<AnySend>);
 
@@ -33,7 +33,7 @@ pub struct Arena {
 
 impl Arena {
     pub const fn new() -> Self {
-        const EMPTY: Mutex<TypeHolderSend> = parking_lot::const_mutex(TypeHolderSend::new());
+        const EMPTY: Mutex<TypeHolderSend> = Mutex::new(TypeHolderSend::new());
         Arena {
             containers: [EMPTY; INTERN_CONTAINER_COUNT],
         }
@@ -82,6 +82,7 @@ impl Arena {
         f(
             self.containers[hash_of_type::<T>() as usize % INTERN_CONTAINER_COUNT]
                 .lock()
+                .unwrap()
                 .get_type_mut(),
         )
     }

src/typearena.rs

@@ -54,7 +54,7 @@ where
     use core::ops::DerefMut;
     for v in CONTAINERS[hash_of_type::<T>() % CONTAINER_COUNT].iter() {
         if let Some(m) = v.0.downcast_ref::<Mutex<HashSet<T>>>() {
-            let mut m = m.lock();
+            let mut m = m.lock().unwrap();
             return f(m.deref_mut());
         }
     }
@@ -67,7 +67,7 @@ where
     // different type.
     for v in CONTAINERS[hash_of_type::<T>() % CONTAINER_COUNT].iter() {
         if let Some(m) = v.0.downcast_ref::<Mutex<HashSet<T>>>() {
-            let mut m = m.lock();
+            let mut m = m.lock().unwrap();
             return f(m.deref_mut());
         }
     }
@@ -76,11 +76,11 @@ where
 
 use super::boxedset;
 use boxedset::HashSet;
-use parking_lot::Mutex;
 use std::borrow::Borrow;
 use std::convert::AsRef;
 use std::fmt::{Debug, Display, Pointer};
 use std::ops::Deref;
+use std::sync::Mutex;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Deserializer, Serialize, Serializer};