</pre>

<p>
If the call never returned, then once again the original program
would never access <code>*p</code> or <code>*q</code>, but the rewritten program would.
And if the call contained synchronizing operations, then the original program
could establish happens before edges preceding the accesses
to <code>*p</code> and <code>*q</code>, but the rewritten program would not.
</p>

<p>

case bool, string:
	printString("type is bool or string")  // type of i is type of x (interface{})
default:
	printString("don't know the type")     // type of i is type of x (interface{})
}
</pre>

<p>
could be rewritten:
</p>

<pre>
v := x  // x is evaluated exactly once
if v == nil {
	i := v                                 // type of i is type of x (interface{})
	printString("x is nil")

case bool, string:
	printString("type is bool or string")  // type of i is type of x (interface{})
default:
	printString("don't know the type")     // type of i is type of x (interface{})
}
</pre>

<p>
could be rewritten:
</p>

<pre>
v := x  // x is evaluated exactly once
if v == nil {
	i := v                                 // type of i is type of x (interface{})
	printString("x is nil")