<p><!-- CL 496156, https://go.dev/issue/59407: log/slog: add vet checks for variadic ...any inputs -->
  The vet tool now reports invalid arguments in calls to functions and methods
  in the structured logging package, <a href="/pkg/log/slog"><code>log/slog</code></a>,
  that accept alternating key/value pairs.
  It reports calls where an argument in a key position is neither a

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> 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

</p>

<p>
The <code>SP</code> pseudo-register is a virtual stack pointer
used to refer to frame-local variables and the arguments being
prepared for function calls.
It points to the highest address within the local stack frame, so references should use negative offsets
in the range [−framesize, 0):
<code>x-8(SP)</code>, <code>y-4(SP)</code>, and so on.
</p>

<p>

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>.