|Subject:||onlyval has incomplete documentation|
Docs for onlyval/only_value say: Returns the only element in LIST for which BLOCK evaluates to true. Sets C<$_> for each item in LIST in turn. Returns C<undef> if no such element has been found. Based on the name of the function I would expect that last sentence to be Returns C<undef> if no such element has been found, or if more than one such element has been found. That's what I'm seeing in List::MoreUtils::PP. The other onlyxxx functions have this same problem.