inlining or not inlining...

[so]

> There are all kinds of extensions popular in C++, but they are not part  
> of Standard C++.

That is because if they don't support an extension (where standard failed  
to provide), people would switch to different compiler that would.
If you mean there are many things a language can't possibly cope with,  
where it could be supported by extensions and inline is one of them,
you would be right and i agree on this point completely.