fier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">x</span> <span class="special">&lt;&lt;</span> <span class="char">'\n'</span><span class="special">;</span>

<span class="comment">// all the following statements should fail to compile because there are </span>
<span class="comment">// no promotion and exception policies specified.</span>
<span class="keyword">constexpr</span> <span class="identifier">safe</span