y hand.
The few cases that arose in the standard repository were mostly bugs.
</p>

<h3 id="unexported">Copying structs with unexported fields</h3>

<p>
The old language did not allow a package to make a copy of a struct value containing unexported fields belonging to a different package.
There was, however, a required exception for a method receiver;
also, the implementations of <code>copy</code> and <code>append</code> have never honored the restriction.
</p>

<p>
Go 1 will allow packages to copy struct v