From 94950afdf8d94fd4ff3fba7e84bf4ce4b16854d0 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 15 Oct 2014 13:33:00 -0400
Subject: [PATCH] reflect: add fast path for FieldByIndex with len(index) = 1

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/152640043
---
 src/reflect/value.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/reflect/value.go b/src/reflect/value.go
index 9c65ee27033..8c320f11b06 100644
--- a/src/reflect/value.go
+++ b/src/reflect/value.go
@@ -857,6 +857,9 @@ func (v Value) Field(i int) Value {
 // FieldByIndex returns the nested field corresponding to index.
 // It panics if v's Kind is not struct.
 func (v Value) FieldByIndex(index []int) Value {
+	if len(index) == 1 {
+		return v.Field(index[0])
+	}
 	v.mustBe(Struct)
 	for i, x := range index {
 		if i > 0 {