On Tue, 2005-10-18 at 01:19 -0500, John Ratliff wrote: > > * John Ratliff: > > > > > On comp.lang.c++, Victor Bazarov says my example program is well-formed > > > standard C++ according to the ISO C++ standard. > > > > > > "Since their address is never taken, the 'foo::A' and 'foo::B' are, in > > > fact, compile-time constant expressions that do not require storage. > > > The objects, therefore, don't need to be defined outside of the class > > > definition. > > > > This analysis argues from the implementation, not from the standard. > > > > The standard requires that you provide a definition if you use the > > constant in a place which does not *require* a constant expression. > > In other words, > > > > int foo[Class::static_const_member]; > > > > is fine without a definition, but > > > > int bar = Class::static_const_member; > > > > is not. > > > > It's strange and smells like a mistake in the standard. > > In response to my message on comp.lang.c++, Greg Comeau replies > > "That's what it says but isn't what it meant. What it meant is what Victor > said, and hence it was acknowledged as a defect since requiring the > definition in all cases was not the intent when member constants were > allowed." > > So, it seems that it is a mistake in the standard. For anyone who doesn't > know him, Greg Comeau is a member of the C++ standards committee. > > I think g++ is trying to do the correct thing (according to the intent of > the committee), even in 3.3, but has one problem area. I am going to leave > out my definitions for now since it will compile on both 3.3 and 3.4 now > that I've removed the ternary expression. This is very important and should be sent to the GCC developers' mailing list so that they can toss this around a bit. Do you subscribe there as well? Thanks, Ernesto > > --John Ratliff > > >
