flag: highlight support for double dashes in docs

Updating examples, to show that double dashes are also permitted. This has been easy to miss previously.

Change-Id: Ib67b4e39fea90ef4cb9e894709c53baedfc18fc2
GitHub-Last-Rev: f7df57b646d6412c1346e85c3a7353a8df41afc6
GitHub-Pull-Request: golang/go#53628
Reviewed-on: https://go-review.googlesource.com/c/go/+/415374
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>

diff --git a/src/flag/flag.go b/src/flag/flag.go
index a0762441a588ab87f190ce51e91780e3888f3cc2..9abf8d769eafdf1299eecdb2662bbdac873fde7a 100644 (file)
--- a/src/flag/flag.go
+++ b/src/flag/flag.go
@@ -49,10 +49,11 @@ The arguments are indexed from 0 through flag.NArg()-1.
 The following forms are permitted:
 
        -flag
+       --flag   // double dashes are also permitted
        -flag=x
        -flag x  // non-boolean flags only
 
-One or two minus signs may be used; they are equivalent.
+One or two dashes may be used; they are equivalent.
 The last form is not permitted for boolean flags because the
 meaning of the command