move external impls to new module

Cargo.toml

@@ -117,7 +117,6 @@ version = "2"
 [dependencies.arbitrary]
 optional = true
 version = "1"
-features = ["derive"]
 
 # Public (unstable): Used in `zerocopy` derive
 [dependencies.zerocopy]

examples/windows_guid.rs

@@ -53,10 +53,7 @@ fn guid_to_uuid() {
 #[cfg(windows)]
 fn uuid_from_cocreateguid() {
     use uuid::{Uuid, Variant, Version};
-    use winapi::{
-        shared::guiddef,
-        um::combaseapi::CoCreateGuid,
-    };
+    use winapi::{shared::guiddef, um::combaseapi::CoCreateGuid};
 
     let mut guid = guiddef::GUID::default();
 

src/external/arbitrary_support.rs

@@ -0,0 +1,43 @@
+use crate::{std::convert::TryInto, Builder, Uuid};
+
+use arbitrary::{Arbitrary, Unstructured};
+
+impl Arbitrary<'_> for Uuid {
+    fn arbitrary(u: &mut Unstructured<'_>) -> arbitrary::Result<Self> {
+        let b = u
+            .bytes(16)?
+            .try_into()
+            .map_err(|_| arbitrary::Error::NotEnoughData)?;
+
+        Ok(Builder::from_random_bytes(b).into_uuid())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use crate::{Variant, Version};
+
+    #[test]
+    fn test_arbitrary() {
+        let mut bytes = Unstructured::new(&[
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        ]);
+
+        let uuid = Uuid::arbitrary(&mut bytes).unwrap();
+
+        assert_eq!(Some(Version::Random), uuid.get_version());
+        assert_eq!(Variant::RFC4122, uuid.get_variant());
+    }
+
+    #[test]
+    fn test_arbitrary_empty() {
+        let mut bytes = Unstructured::new(&[]);
+
+        // Ensure we don't panic when building an arbitrary `Uuid`
+        let uuid = Uuid::arbitrary(&mut bytes);
+
+        assert!(uuid.is_err());
+    }
+}

src/external/mod.rs

@@ -0,0 +1,6 @@
+#[cfg(feature = "arbitrary")]
+mod arbitrary_support;
+#[cfg(feature = "serde")]
+mod serde_support;
+#[cfg(feature = "slog")]
+mod slog_support;

src/lib.rs

@@ -190,9 +190,6 @@ compile_error!("The `zerocopy-unstable` feature is unstable and may break betwee
 #[cfg(feature = "zerocopy-unstable")]
 use zerocopy::{AsBytes, FromBytes, Unaligned};
 
-#[cfg(feature = "arbitrary")]
-use arbitrary::Arbitrary;
-
 mod builder;
 mod error;
 mod parser;
@@ -210,10 +207,8 @@ mod v5;
 
 #[cfg(feature = "rng")]
 mod rng;
-#[cfg(feature = "serde")]
-mod serde_support;
-#[cfg(feature = "slog")]
-mod slog_support;
+
+mod external;
 
 #[cfg(feature = "macros")]
 #[macro_use]
@@ -359,7 +354,6 @@ pub enum Variant {
     feature = "zerocopy-unstable",
     derive(AsBytes, FromBytes, Unaligned)
 )]
-#[cfg_attr(feature = "arbitrary", derive(Arbitrary))]
 #[repr(transparent)]
 pub struct Uuid(Bytes);