[go-nuts] gob on structure having mutex

Hi,

Gob encoding for below structure does not work :
type A struct {
   sync.RWMutex
   ID int
   Value string
}
because sync.RWMutex does not have any exported field.

If I do:
type A struct {
   lock sync.RWMutex
   ID int
   Value string
}
now it works, as lock is a private field.

But then I have to do A.lock.Lock(), which doesn't sound very correct.

Other approach can be :
type B struct {
    A
    sync.RWMutex
}

Can you please tell me if there is a better approach to this? As both look
difficult to justify, unless you know its due to requirement of gob
encoding.