> * 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. --John Ratliff
