From 9f6f348b2feb236e7b9a51e8f4c5bab979a34fe6 Mon Sep 17 00:00:00 2001
From: Bryan Chen <xlchen1291@gmail.com>
Date: Thu, 1 Apr 2021 16:04:54 +1300
Subject: [PATCH] add Handler

---
 traits/src/lib.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/traits/src/lib.rs b/traits/src/lib.rs
index d8dfbab39..2aa3e19c9 100644
--- a/traits/src/lib.rs
+++ b/traits/src/lib.rs
@@ -1,7 +1,8 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use codec::{Decode, Encode};
-use sp_runtime::RuntimeDebug;
+use impl_trait_for_tuples::impl_for_tuples;
+use sp_runtime::{DispatchResult, RuntimeDebug};
 use sp_std::{
 	cmp::{Eq, PartialEq},
 	prelude::Vec,
@@ -64,11 +65,23 @@ pub struct TimestampedValue<Value: Ord + PartialOrd, Moment> {
 	pub timestamp: Moment,
 }
 
-#[impl_trait_for_tuples::impl_for_tuples(30)]
+#[impl_for_tuples(30)]
 pub trait Happened<T> {
 	fn happened(t: &T);
 }
 
+pub trait Handler<T> {
+	fn handle(t: &T) -> DispatchResult;
+}
+
+#[impl_for_tuples(30)]
+impl<T> Handler<T> for Tuple {
+	fn handle(t: &T) -> DispatchResult {
+		for_tuples!( #( Tuple::handle(t); )* );
+		Ok(())
+	}
+}
+
 pub trait Contains<T> {
 	fn contains(t: &T) -> bool;
 }