From the error message, it looks like you’re not allowed to take the address of a parenthesized expression. It’s suggesting that you rewrite
fPtr = &(myfoo::foo); // main.cpp:14
to
fPtr = &myfoo::foo;
This is due to a portion of the spec (ยง5.3.1/3) that reads
A pointer to member is only formed when an explicit & is used and its operand is a qualified-id not enclosed in parentheses […]
(my emphasis). I’m not sure why this is a rule (and I didn’t actually know this until now), but this seems to be what the compiler is complaining about.
Hope this helps!