Error during compilation

[hervema]

Hello. I know it's a very old topic/code, however it could be exactly what I'm looking for :-)

I have an error during compilation I totally not able to understand :-(

src/async.h:65:28: error: member template 'R function::run(Tn ...)' may not have virt-specifiers
R run(Tn ... args) override;
^~~~~~~~

It would be great to have from you some tips to resolve this error.

Thanks in advance !

Regards,

hervema