On 20 Feb 2016 6:54 p.m., "H.J. Lu" <hjl.to...@gmail.com> wrote: > > On Sat, Feb 20, 2016 at 4:57 PM, Matthijs van Duin > <matthijsvand...@gmail.com> wrote: > > On 20 February 2016 at 23:35, H.J. Lu <hjl.to...@gmail.com> wrote: > >> Can a compiler tell if a copy constructor or destructor is trivial > >> from the class declaration without function body? > > > > Yes, the mere presence of the declaration suffices to render it > > non-trivial (unless explicitly declared "= default" like I did with > > the default constructor, in which case there's no function body). > > How about this? > > An empty type is a type where it and all of its subobjects (recursively) > are of class, structure, union, or array type. An empty type may only > have static member functions, default constructor, default copy > constructor, default copy assignment operator or default destructor.
No, that's the wrong rule still. Please leave the C++ rule here to the C++ ABI rather than trying to reinvent it. Whether a type is empty is completely orthogonal to whether it must be passed through memory for C++ ABI / semantics reasons. > No memory slot nor register should be used to pass or return an > object of empty type. > > -- > H.J.
_______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
