On Jun 3, 2005, at 1:23 PM, David Abrahams wrote:
Okay, here's your next challenge. This is with the very latest Comeau alpha release compiler.
"c:\boost/boost/type_traits/is_member_function_pointer.hpp", line 67: warning #1290-D: non-POD class type passed through ellipsis
That's ominous! This is exactly what I was talking about when: On May 26, 2005, at 9:02 AM, Howard Hinnant wrote:
I haven't dug into boost::is_pointer, but I'm guessing it involves a tentative binding to an ellipsis:
template <class U> static two test(...);
5.2.2p7 says that binding a non-POD class type to an ellipsis has undefined behavior. CodeWarrior's behavior in this context is to try to pass the type by value by using the type's copy constructor, which in this case is private, and thus triggers the access error.
The scary part is that we do so many useful things these days by tentatively passing non-POD's past an ellipses, though only at compile time, never at run time. But the compiler is not making that distinction. This is a big problem, and I suspect it will need to be addressed at the standards level. I don't have a solution yet. -Howard