[go-nuts] compilator optimisation for a string as a map key

Hello,
According to David's pres (
http://go-talks.appspot.com/github.com/davecheney/presentations/writing-high-performance-go.slide#30)
<http://go-talks.appspot.com/github.com/davecheney/presentations/writing-high-performance-go.slide#30>,
if you want use []byte as map key, the compiler implements some
optimization (avoid the conversion []byte -> string) when you do this:

var m map[string]string
v, ok := m[string(bytes)]



but not:

key := string(bytes)
val, ok := m[key]



As net.IP is []byte, does the compiler implement the same optimization when
you do this :

var m map[string]string
val, ok := m[string(net.IPv4zero)]

or I have to do this:
var m map[string]string
val, ok := m[string([]byte(net.IPv4zero))]

Thx in adv (special thx to Dave for this pres and his kindness :) )
Jérôme