From 382e99d06e8bdc2818704e4a22d23a11110803fa Mon Sep 17 00:00:00 2001
From: Jae Kwon <jae@tendermint.com>
Date: Mon, 2 Apr 2018 01:46:24 -0700
Subject: [PATCH] Add IsTypedNil

---
 common/nil.go | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 common/nil.go

diff --git a/common/nil.go b/common/nil.go
new file mode 100644
index 00000000..c7617f08
--- /dev/null
+++ b/common/nil.go
@@ -0,0 +1,18 @@
+package common
+
+import "reflect"
+
+// Go lacks a simple and safe way to see if something is a typed nil.
+// See:
+//  - https://dave.cheney.net/2017/08/09/typed-nils-in-go-2
+//  - https://groups.google.com/forum/#!topic/golang-nuts/wnH302gBa4I/discussion
+//  - https://github.com/golang/go/issues/21538
+func IsTypedNil(o interface{}) bool {
+	rv := reflect.ValueOf(o)
+	switch rv.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice:
+		return rv.IsNil()
+	default:
+		return false
+	}
+}