gnu: Add rust-arc-swap-0.3.

* gnu/packages/crates-io.scm (rust-arc-swap-0.3): New variable.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/crates-io.scm

@@ -218,6 +218,37 @@ text or blue underlined text, on ANSI terminals.")
      "Approximate floating point equality comparisons and assertions.")
     (license license:asl2.0)))
 
+(define-public rust-arc-swap-0.3
+  (package
+    (name "rust-arc-swap")
+    (version "0.3.11")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "arc-swap" version))
+       (file-name
+        (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "0ha8724dpki985v52ifq5sd98xvpa5q51hyma52di75dbqbn4imw"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:skip-build? #t
+       #:cargo-development-inputs
+       (("rust-crossbeam" ,rust-crossbeam-0.7)
+        ("rust-crossbeam-utils" ,rust-crossbeam-utils-0.6)
+        ("rust-itertools" ,rust-itertools-0.8)
+        ("rust-lazy-static" ,rust-lazy-static-1.3)
+        ("rust-model" ,rust-model-0.1)
+        ("rust-num-cpus" ,rust-num-cpus-1.10)
+        ("rust-parking-lot" ,rust-parking-lot-0.8)
+        ("rust-proptest" ,rust-proptest-0.9)
+        ("rust-version-sync" ,rust-version-sync-0.8))))
+    (home-page "https://github.com/vorner/arc-swap")
+    (synopsis "Atomically swappable Arc")
+    (description "This package provides an atomically swappable Arc.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-arrayvec-0.4
   (package
     (name "rust-arrayvec")