[cfe-dev] Warnings: -w options and default

[Chris Lattner]

On Sep 13, 2010, at 8:42 AM, Douglas Gregor wrote:

>> 
>> May I ask what danger is there in that construct that motivates a warning by default? If I were to push a bug report to the Boost people, I'd better be clad in certainties.
> 
> IIRC, Visual C++ actually cares about the struct/class difference more than it should (I don't recall the details), so a portable code-base might want this warning. In any case, it isn't important enough to turn on by default, so we didn't.

It is very dangerous in VC++, it changes the mangling of the type in some cases, so you can get link errors if you mismatch tags.

-Chris