1 files changed, 23 insertions, 1 deletions
diff --git a/common/types/types.go b/common/types/types.go
index 95e72d99b..f03031439 100644
--- a/common/types/types.go
+++ b/common/types/types.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The Hugo Authors. All rights reserved.
+// Copyright 2019 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@ package types
 
 import (
 	"fmt"
+	"reflect"
 
 	"github.com/spf13/cast"
 )
@@ -56,3 +57,24 @@ func NewKeyValuesStrings(key string, values ...string) KeyValues {
 type Zeroer interface {
 	IsZero() bool
 }
+
+// IsNil reports whether v is nil.
+func IsNil(v interface{}) bool {
+	if v == nil {
+		return true
+	}
+
+	value := reflect.ValueOf(v)
+	switch value.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return value.IsNil()
+	}
+
+	return false
+}
+
+// DevMarker is a marker interface for types that should only be used during
+// development.
+type DevMarker interface {
+	DevOnly()
+}