In the note:
"For a derived class \tcode{D}, a typical implementation of this function will compute \tcode{dynamic_cast<const D*>(&other)} and go no further (i.e., return \tcode{false}) if it returns \tcode{nullptr}."
what is "it"?

e-mail from Richard:

I'm guessing "it" means the dynamic_cast expression. But in that case the wording is wrong, as it's not a function call and thus cannot return a value. Seems like this is something we can handle editorially, as this is non-normative; please either file an editorial issue or a pull request.