Removed dependency on spin crate and its corresponding trait implem…

…entations.

Cargo.toml

@@ -15,8 +15,3 @@ An unsafe marker trait for types like Box and Rc that dereference to a stable ad
 default = ["std"]
 std = []
 alloc = []
-spin_mutex = [ "spin" ]
-
-[dependencies.spin]
-version = "0.4.5"
-optional = true

README.md

@@ -11,7 +11,13 @@ Enable the "alloc" feature (with default-features disabled) to have this trait b
 * `alloc::arc::Arc`
 * `alloc::string::String`
 
-Enable the "spin_mutex" feature (with default-features disabled) to have this trait be implemented for the following types from the [spin](https://crates.io/crates/spin) crate:
-* `spin::MutexGuard`
-* `spin::RwLockReadGuard`
-* `spin::RwLockWriteGuard`
+For example, this crate can be built with alloc support via the following command:    
+`cargo build --no-default-features --features alloc`
+
+Or added as a `Cargo.toml` dependency as follows:
+```
+[dependencies.stable_deref_trait]
+version = "<version>"
+default-features = false
+features = [ "alloc" ]
+```

src/lib.rs

@@ -14,7 +14,7 @@ It is intended to be used by crates such as [owning_ref](https://crates.io/crate
 no_std support can be enabled by disabling default features (specifically "std"). In this case, the trait will not be implemented for the std types mentioned above, but you can still use it for your own types.
 */
 
-#![feature(alloc)]
+#![cfg_attr(feature = "alloc", feature(alloc))]
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
@@ -24,9 +24,6 @@ extern crate core;
 #[cfg(feature = "alloc")]
 extern crate alloc;
 
-#[cfg(feature = "spin")]
-extern crate spin;
-
 use core::ops::Deref;
 
 
@@ -165,9 +162,6 @@ use alloc::string::String;
 
 #[cfg(feature = "std")]
 use std::sync::{MutexGuard, RwLockReadGuard, RwLockWriteGuard};
-#[cfg(feature = "spin")]
-use spin::{MutexGuard, RwLockReadGuard, RwLockWriteGuard};
-
 
 #[cfg(feature = "std")]
 use std::cell::{Ref, RefMut};
@@ -195,11 +189,11 @@ unsafe impl<T: ?Sized> CloneStableDeref for Arc<T> {}
 unsafe impl<'a, T: ?Sized> StableDeref for Ref<'a, T> {}
 // #[cfg(any(feature = "std", feature = "alloc"))]
 unsafe impl<'a, T: ?Sized> StableDeref for RefMut<'a, T> {}
-#[cfg(any(feature = "std", feature = "spin"))]
+#[cfg(feature = "std")]
 unsafe impl<'a, T: ?Sized> StableDeref for MutexGuard<'a, T> {}
-#[cfg(any(feature = "std", feature = "spin"))]
+#[cfg(feature = "std")]
 unsafe impl<'a, T: ?Sized> StableDeref for RwLockReadGuard<'a, T> {}
-#[cfg(any(feature = "std", feature = "spin"))]
+#[cfg(feature = "std")]
 unsafe impl<'a, T: ?Sized> StableDeref for RwLockWriteGuard<'a, T> {}
 
 unsafe impl<'a, T: ?Sized> StableDeref for &'a T {}