https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84076
--- Comment #5 from sgunderson at bigfoot dot com --- Ah, so it's allowed to send structs and classes, just not non-PODs. So that's why the conversion to a pointer happens.
sgunderson at bigfoot dot com Tue, 30 Jan 2018 10:17:07 -0800
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84076
--- Comment #5 from sgunderson at bigfoot dot com --- Ah, so it's allowed to send structs and classes, just not non-PODs. So that's why the conversion to a pointer happens.