[Bug target/79671] [7 Regression] mapnik miscompilation on armv7hl since r235622

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79671

--- Comment #55 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Bernd Edlinger from comment #53)
> The boost code was: "this->functor = f.functor;"

And I still don't understand why may_alias doesn't help on the type of
this->functor.