Implement arbitrary behind a feature flag

Author: Andrew Jeffery

src/tools/rust-analyzer/lib/smol_str/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "smol_str"
-version = "0.1.17"
+version = "0.1.18"
 description = "small-string optimized string type with O(1) clone"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/matklad/smol_str"
@@ -9,6 +9,7 @@ edition = "2018"
 
 [dependencies]
 serde = { version = "1", optional = true, default_features = false, features = [ "std" ] }
+arbitrary = { version = "1", optional = true }
 
 [dev-dependencies]
 proptest = "0.10"

src/tools/rust-analyzer/lib/smol_str/src/lib.rs

@@ -300,6 +300,14 @@ impl Borrow<str> for SmolStr {
     }
 }
 
+#[cfg(feature = "arbitrary")]
+impl<'a> arbitrary::Arbitrary<'a> for SmolStr {
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> Result<Self, arbitrary::Error> {
+        let s = <&str>::arbitrary(u)?;
+        Ok(SmolStr::new(s))
+    }
+}
+
 const INLINE_CAP: usize = 22;
 const N_NEWLINES: usize = 32;
 const N_SPACES: usize = 128;