From 7e3a4fb4aa14bbc0d5c0c36a55504c00aaababb7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maximilian=20Kru=CC=88ger?= <kruemaxi@googlemail.com>
Date: Fri, 16 Feb 2018 09:56:08 +0100
Subject: [PATCH] impl feature gated quickcheck arbitrary for hash

---
 Cargo.toml  |  2 ++
 src/hash.rs | 23 +++++++++++++++++++++++
 src/lib.rs  |  4 ++++
 3 files changed, 29 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 9b2a91e..722dd5f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,8 +11,10 @@ heapsize = { version = "0.4", optional = true }
 libc = { version = "0.2", optional = true, default-features = false }
 rand = { version = "0.4", optional = true }
 rustc-hex = { version = "1.0", optional = true }
+quickcheck = { version = "0.6", optional = true }
 
 [features]
 default = ["libc"]
 std = ["rustc-hex", "rand"]
 heapsizeof = ["heapsize"]
+impl_quickcheck_arbitrary = ["quickcheck"]
diff --git a/src/hash.rs b/src/hash.rs
index 990294b..156f828 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -301,6 +301,7 @@ macro_rules! construct_hash {
 		impl_std_for_hash!($from, $size);
 		impl_heapsize_for_hash!($from);
 		impl_libc_for_hash!($from, $size);
+		impl_quickcheck_arbitrary_for_hash!($from, $size);
 	}
 }
 
@@ -463,3 +464,25 @@ macro_rules! impl_libc_for_hash {
 		}
 	}
 }
+
+#[cfg(feature="impl_quickcheck_arbitrary")]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_quickcheck_arbitrary_for_hash {
+	($name: ty, $n_bytes: tt) => {
+		impl $crate::quickcheck::Arbitrary for $name {
+			fn arbitrary<G: $crate::quickcheck::Gen>(g: &mut G) -> Self {
+				let mut res = [0u8; $n_bytes];
+				g.fill_bytes(&mut res[..$n_bytes]);
+				res.as_ref().into()
+			}
+		}
+	}
+}
+
+#[cfg(not(feature="impl_quickcheck_arbitrary"))]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_quickcheck_arbitrary_for_hash {
+	($name: ty, $n_bytes: tt) => {}
+}
diff --git a/src/lib.rs b/src/lib.rs
index cf5d72f..77d9f0d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,5 +32,9 @@ pub extern crate rustc_hex;
 #[doc(hidden)]
 pub extern crate rand;
 
+#[cfg(feature="impl_quickcheck_arbitrary")]
+#[doc(hidden)]
+pub extern crate quickcheck;
+
 mod hash;
 pub use hash::*;