From: Matt Layher <mdlayher@gmail.com>
Date: Fri, 30 Sep 2016 21:23:24 +0000 (-0400)
Subject: context: discourage use of basic types as keys in WithValue
X-Git-Tag: go1.8beta1~1091
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=c5f064ee49e98c00c7959fdf095e2c61ff0747b8;p=gostls13.git

context: discourage use of basic types as keys in WithValue

Fixes #17302

Change-Id: I375d5d4f2714ff415542f4fe56a548e53c5e8ba6
Reviewed-on: https://go-review.googlesource.com/30134
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
---

diff --git a/src/context/context.go b/src/context/context.go
index 3afa3e90d2..41a5cefef9 100644
--- a/src/context/context.go
+++ b/src/context/context.go
@@ -443,7 +443,9 @@ func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) {
 // Use context Values only for request-scoped data that transits processes and
 // APIs, not for passing optional parameters to functions.
 //
-// The provided key must be comparable.
+// The provided key must be comparable and should not be
+// of type string or any other built-in type.
+// Users of WithValue should define their own types for keys.
 func WithValue(parent Context, key, val interface{}) Context {
 	if key == nil {
 		panic("nil key")