From c5f064ee49e98c00c7959fdf095e2c61ff0747b8 Mon Sep 17 00:00:00 2001 From: Matt Layher Date: Fri, 30 Sep 2016 17:23:24 -0400 Subject: [PATCH] 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 --- src/context/context.go | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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") -- 2.48.1