Repot and fix a ser/de bug.

substrate/wasm-runtime/polkadot/src/support/hashable.rs

@@ -0,0 +1,38 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Hashable trait.
+
+use slicable::Slicable;
+use runtime_support::{blake2_256, twox_128, twox_256};
+
+pub trait Hashable: Sized {
+	fn blake2_256(&self) -> [u8; 32];
+	fn twox_128(&self) -> [u8; 16];
+	fn twox_256(&self) -> [u8; 32];
+}
+
+impl<T: Slicable> Hashable for T {
+	fn blake2_256(&self) -> [u8; 32] {
+		blake2_256(&self.to_vec())
+	}
+	fn twox_128(&self) -> [u8; 16] {
+		twox_128(&self.to_vec())
+	}
+	fn twox_256(&self) -> [u8; 32] {
+		twox_256(&self.to_vec())
+	}
+}