t has no allocator.</span>

<span class="identifier">constexpr</span> <span class="identifier">checked_uint128_t</span>   <span class="identifier">k</span> <span class="special">=</span> <span class="special">-</span><span class="number">1</span><span class="special">;</span> <span class="comment">// Error, checked type is not a literal type as we need runtime error checking.</span>
<span class="identifier">constexpr</span> <span class="identifier">cpp_int</span>             <span class="identifier">l</span