AW: [xsd-users] how to get type information from tree nodes

[Lena Herscheid]

Thanks for the quick answer!

When saying that RTTI was not portable, I was referring to platform
differences with typeidx().name().
But it surely is possible to compare to the typeid of a "fresh class
instance" instead of hard coded strings. 
So I'll certainly find a solution.

Cheers
Lena

-----Ursprüngliche Nachricht-----
Von: Boris Kolpackov [mailto:boris at codesynthesis.com] 
Gesendet: 21 August 2013 20:16
An: Lena Herscheid
Cc: xsd-users at codesynthesis.com
Betreff: Re: [xsd-users] how to get type information from tree nodes

Hi Lena,

Lena Herscheid <lenaherscheid at gmail.com> writes:

> Is it possible with cxx-tree to generate member functions returning 
> the typename of the current node (as string)?

No, there is no such support.


> I'm asking because the alternative way of efficiently determining the 
> type of any during runtime requires some RTTI which is not portable.

I am not sure what you mean by "some RTTI", but standard C++ RTTI (i.e.,
dynamic_cast, typeid) are very much portable. Some projects may choose to
disable this support in order to minimize code size, but that's another
story.

So if you need a type name in C++/Tree, then typeid(x).name () is the
recommended way. If, however, you want to find whether x is of a particular
dynamic type, then use dynamic_cast, it will be much faster than any custom
RTTI with string comparison:

base& x = ...

if (derived1* d1 = dynamic_cast<derived1*> (&x)) {
  // x is derived1
}
else if (derived2* d2 = dynamic_cast<derived2*> (&x)) {
  // x is derived2
}

...

else
{
  // x is something else
}

Boris