Visual C++ Tip: How to Enable Standard C++ Keywords

The people at Microsoft responsible for Visual C++ need to beaten with a stick. Those responsible for the documentation should be beaten severely.

Once again, I just finished another round of frustration with the non-compliance problems of Visual C++ 8. One would think that by six years after the ISO standard, they would get around to having all the embarrassingly glaring compliance issues sorted out, but sadly, it is still the case that simple, conforming C++ programs will not easily compile.

My current frustration is that, by default, Visual C++ has the boolean operator keywords disabled. That's right, by default, Visual C++ has certain, standard C++ keywords disabled. And it isn't some obscure functionality that I'm referring to, it's the keywords for the logical boolean operators.

It is possible to enable them with the option /Za. To be clear on this, we can refer to the MSDN documentation for the /Za option,

/Za flags language constructs not compatible with either ANSI C++ or ANSI C as errors. /Ze enables Microsoft extensions.

Uh oh, it looks like Microsoft tied two bits of unrelated functionality together into one compiler option, and left one of the bits undocumented. I think I have the full story figured out now, but caveat lector! We've landed in an undocumented, side-effect territory. It seems that we can either have the standard keywords or the language extensions, but not both. Now, most of the language extensions are useless, losing them is no problem, but there is an exception here. The keyword "extern" is erroneously considered a language extension by Microsoft. If you need that very useful keyword, you may run into problems.

Like I wrote at the start of this post, the people at Microsoft responsible for Visual C++ need to beaten with a stick. Those responsible for the documentation should be beaten severely. The design choice here is a shining example as to just how bad the compiler actually is.