No <a href="#Run_time_panics">run-time panic</a> occurs in this case.
</p>


<h3 id="Calls">Calls</h3>

<p>
Given an expression <code>f</code> of function type
<code>F</code>,
</p>

<pre>
f(a1, a2, … an)
</pre>

<p>
calls <code>f</code> with arguments <code>a1, a2, … an</code>.
Except for one special case, arguments must be single-valued expressions

initialization in the presence of multiple goroutines
through the use of the <code>Once</code> type.
Multiple threads can execute <code>once.Do(f)</code> for a particular <code>f</code>,
but only one will run <code>f()</code>, and the other calls block
until <code>f()</code> has returned.
</p>

<p class="rule">
The completion of a single call of <code>f()</code> from <code>once.Do(f)</code>

No <a href="#Run_time_panics">run-time panic</a> occurs in this case.
</p>


<h3 id="Calls">Calls</h3>

<p>
Given an expression <code>f</code> with a <a href="#Core_types">core type</a>
<code>F</code> of <a href="#Function_types">function type</a>,
</p>

<pre>
f(a1, a2, … an)
</pre>

<p>
calls <code>f</code> with arguments <code>a1, a2, … an</code>.