into:

<pre>
n := 0
local := *shared
for i := 0; i < m; i++ {
	n += local
}
</pre>

<p>
provided it can be proved that <code>*shared</code> will not fault on access,
because the potential added read will not affect any existing concurrent reads or writes.
On the other hand, the rewrite would not be valid in a source-to-source translator.
</p>

<h2 id="conclusion">Conclusion</h2>

<p>

The number of map elements is called its length.
For a map <code>m</code>, it can be discovered using the
built-in function <a href="#Length_and_capacity"><code>len</code></a>
and may change during execution. Elements may be added during execution
using <a href="#Assignments">assignments</a> and retrieved with
<a href="#Index_expressions">index expressions</a>; they may be removed with the

language.
</p>

<p>
A link of the form [<a href="#Language_versions">Go 1.xx</a>] indicates that a described
language feature (or some aspect of it) was changed or added with language version 1.xx and
thus requires at minimum that language version to build.
For details, see the <a href="#Language_versions">linked section</a>
in the <a href="#Appendix">appendix</a>.
</p>