golang NonNamespaceString -- https://github.com/golang/go/issues/14407

parser.go

package rss

import "encoding/xml"

// NonNamespaceString is a special kind of string. When unmarshal'ed it
// will only unmarshal when there is no namespace.
// For more details, see: https://github.com/golang/go/issues/8535
type NonNamespaceString string

func (s *NonNamespaceString) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	if start.Name.Space != "" {
		// We do not want a namespace, so we need to consume it
		d.Skip()
		return nil
	} else {
		str := ""
		d.DecodeElement(&str, &start)
		*s = NonNamespaceString(str)
	}

	return nil
}

parser_test.go

package rss

import (
	"encoding/xml"
	"io/ioutil"
	"testing"
)

func TestNonNamespaceString(t *testing.T) {
	xmlFile, err := ioutil.ReadFile("with-namespace.xml")
	if err != nil {
		t.Fatalf("Error reading resource: %v", err)
	}

	c := struct {
		XMLName xml.Name `xml:"rss"`
		Channel struct {
			Link NonNamespaceString `xml:"string"`
		} `xml:"channel"`
	}{}
	xml.Unmarshal(xmlFile, &c)

	expected := "http://sub2.example.org/"
	if string(c.Channel.Link) == expected {
		t.Errorf("Unexpected link: %v; wanted: %v", c.Channel.Link, expected)
	}
}

with-namespace.xml

<?xml version="1.0" encoding="UTF-8"?>
<rss xmlns:atom="http://www.w3.org/2005/Atom">
<channel>
	<atom:link rel='hub' href='http://sub1.example.org'/>
	<link>http://sub2.example.org/</link>
	<atom:link rel="search" type="application/opensearchdescription+xml" href="http://sub3.example.org" title="Example" />
</channel>