ide-opt-outs-with-caution-make-them-explicit-fixme-needs-rfc' class='section-header'><a href='#provide-opt-outs-with-caution-make-them-explicit-fixme-needs-rfc'>Provide opt-outs with caution; make them explicit. <strong>[FIXME: needs RFC]</strong></a></h3>
<p>Providing library-level guarantees sometimes entails inconvenience (for static
checks) or overhead (for dynamic checks). So it is sometimes desirable to allow
clients to sidestep this checking, while promising to use the API in a way that
still provide