Add the alloc feature

Cargo.toml

@@ -29,6 +29,7 @@ std = [
   "crossbeam-queue",
   "crossbeam-utils/std",
 ]
+alloc = ["crossbeam-epoch/alloc", "crossbeam-utils/alloc"]
 
 [dependencies]
 cfg-if = "0.1.2"

ci/crossbeam-epoch.sh

@@ -23,5 +23,6 @@ if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
 
     # Check for no_std environment.
     cargo check --target thumbv7m-none-eabi --no-default-features
-    cargo check --target thumbv7m-none-eabi --no-default-features --features nightly
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc,nightly
 fi

ci/crossbeam-skiplist.sh

@@ -15,5 +15,6 @@ if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
 
     # Check for no_std environment.
     cargo check --target thumbv7m-none-eabi --no-default-features
-    cargo check --target thumbv7m-none-eabi --no-default-features --features nightly
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc,nightly
 fi

ci/crossbeam-utils.sh

@@ -15,5 +15,6 @@ if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
 
     # Check for no_std environment.
     cargo check --target thumbv7m-none-eabi --no-default-features
-    cargo check --target thumbv7m-none-eabi --no-default-features --features nightly
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc,nightly
 fi

ci/crossbeam.sh

@@ -15,5 +15,6 @@ if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
 
     # Check for no_std environment.
     cargo check --target thumbv7m-none-eabi --no-default-features
-    cargo check --target thumbv7m-none-eabi --no-default-features --features nightly
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc
+    cargo check --target thumbv7m-none-eabi --no-default-features --features alloc,nightly
 fi

crossbeam-epoch/Cargo.toml

@@ -19,6 +19,7 @@ categories = ["concurrency", "memory-management", "no-std"]
 default = ["std"]
 nightly = ["crossbeam-utils/nightly", "arrayvec/use_union"]
 std = ["crossbeam-utils/std", "lazy_static"]
+alloc = ["crossbeam-utils/alloc"]
 sanitize = [] # Makes it more likely to trigger any potential data races.
 
 [dependencies]

crossbeam-epoch/src/lib.rs

@@ -65,16 +65,15 @@ extern crate cfg_if;
 extern crate core;
 
 cfg_if! {
-    if #[cfg(feature = "nightly")] {
+    if #[cfg(feature = "alloc")] {
         extern crate alloc;
-    } else {
-        #[cfg(feature = "std")]
+    } else if #[cfg(feature = "std")] {
         extern crate std as alloc;
     }
 }
 
 cfg_if! {
-    if #[cfg(any(feature = "std", feature = "nightly"))] {
+    if #[cfg(any(feature = "alloc", feature = "std"))] {
         extern crate arrayvec;
         extern crate crossbeam_utils;
         #[macro_use]

crossbeam-skiplist/Cargo.toml

@@ -19,6 +19,7 @@ categories = ["algorithms", "concurrency", "data-structures", "no-std"]
 default = ["std"]
 nightly = ["crossbeam-epoch/nightly", "crossbeam-utils/nightly"]
 std = ["crossbeam-epoch/std", "crossbeam-utils/std"]
+alloc = ["crossbeam-epoch/alloc", "crossbeam-utils/alloc"]
 
 [dependencies]
 cfg-if = "0.1.2"

crossbeam-skiplist/src/lib.rs

@@ -10,16 +10,15 @@ extern crate cfg_if;
 extern crate core;
 
 cfg_if! {
-    if #[cfg(feature = "nightly")] {
+    if #[cfg(feature = "alloc")] {
         extern crate alloc;
-    } else {
-        #[cfg(feature = "std")]
+    } else if #[cfg(feature = "std")] {
         extern crate std as alloc;
     }
 }
 
 cfg_if! {
-    if #[cfg(any(feature = "std", feature = "nightly"))] {
+    if #[cfg(any(feature = "alloc", feature = "std"))] {
         extern crate crossbeam_epoch as epoch;
         extern crate crossbeam_utils as utils;
         extern crate scopeguard;

crossbeam-utils/Cargo.toml

@@ -19,6 +19,7 @@ categories = ["algorithms", "concurrency", "data-structures", "no-std"]
 default = ["std"]
 nightly = []
 std = ["lazy_static"]
+alloc = []
 
 [dependencies]
 cfg-if = "0.1.2"

crossbeam-utils/src/lib.rs

@@ -37,10 +37,9 @@ extern crate cfg_if;
 extern crate core;
 
 cfg_if! {
-    if #[cfg(feature = "nightly")] {
+    if #[cfg(feature = "alloc")] {
         extern crate alloc;
-    } else {
-        #[cfg(feature = "std")]
+    } else if #[cfg(feature = "std")] {
         extern crate std as alloc;
     }
 }

src/lib.rs

@@ -53,10 +53,9 @@ extern crate cfg_if;
 extern crate core;
 
 cfg_if! {
-    if #[cfg(feature = "nightly")] {
+    if #[cfg(feature = "alloc")] {
         extern crate alloc;
-    } else {
-        #[cfg(feature = "std")]
+    } else if #[cfg(feature = "std")] {
         extern crate std as alloc;
     }
 }