  myStruct := p.NewStruct(23)
    copyOfMyStruct := myStruct
    fmt.Println(myStruct, copyOfMyStruct)
</pre>

<p>
will show that the secret field of the struct has been copied to the new value.
</p>

<p>
<em>Updating</em>:
This is a new feature, so existing code needs no changes.
</p>

<h3 id="equality">Equality</h3>

<p>
Before Go 1, the language did not define equality on struct and array values.
This meant,
among other things, that structs and arrays could not be used as map keys.
On the other hand, Go 