True, though here the hack is incredibly unintuitive for the programmer. You have to declare the constructor, but then leave it unimplemented. Not to mention the compiler error that should catch this now only occurs at link time, and linking errors are even more cryptic to grok.

When they made RVO mandatory, they should’ve removed the constructor declaration requirement as well, instead of a half-ass solution like this.

As a final nail in the coffin, std::is_move_constructible<> suddenly returns true for this non-move-constructible type 😉

Well, it’s really interesting that this is a hack that works, but you’re really fighting the compiler here.

This is making me all the happier I switched to Rust 😂

This is the only way really to move forward with ISA extensions.

Though, I think for this update we don’t need to be too concerned. Since it changes the code in such an extensive way, compiler writers will be strongly incentivised to produce this duplicate path themselves. Instead of letting the burden of dispatching fall on the programmer like with AVX and friends