> On Dec 17, 2012, at 2:44 AM, Markos Zaharioudakis <[email protected]> wrote: > > > size:size(<a><b>foo</b></a>) returns 101. This is wrong because just > sizeof(ElementNode) is 52 and the tree <a><b>foo</b></a> consists of 2 element > nodes, one text node and one (hidden) attribute node. > > > > The reason for this wrong result is in this struct: > > > > template<typename T> > > struct size_traits<T*,false> { > > static size_t alloc_sizeof( T *p ) { > > return p ? mem_sizeof( *p ) : 0; > > } > > }; > > > > Basically, an InternalNode has a vector of XmlNode*. So, the above struct is > instantiated with T being XmlNode. Then, mem_sizeof(XmlNode) is called > returning just 20 (== sizeof(XmlNode)). > > I've looked at this a bit more and I still don't understand why it's wrong. > Ignoring everything else, the alloc_size() specialization for pointers seems > correct. > > For a vector<XmlNode*>, it should iterate through the vector's elements. For > each element, it should call the above alloc_sizeof() for XmlNode*. That in > turn should call mem_sizeof(XmlNode) which is sizeof(XmlNode) + > alloc_sizeof(XmlNode).
Here is the 1st problem: inside mem_sizeof(const XmlNode& t), sizeof(T) (or sizeof(t)) should return 52 if t is actually an ElementNode. Of course, this is not possible since sizeof(T) is computed statically (i.e., at compile time). > alloc_sizeof(XmlNode) turns into > size_traits<XmlNode>::alloc_sizeof(t). > And here is the 2nd problem: alloc_sizeof(XmlNode) turns into size_traits<XmlNode, false>::alloc_sizeof(t), which returns 0. Somehow, the trick with the has_alloc_size class does not work. > XmlNode is derived from store::Item that has a virtual alloc_size(). The > specialization of size_traits for classes that have an alloc_size() member > function is called. Therefore, I don't see where the mistake is. > > - Paul Try stepping through this example with gdb, and you will see it yourself. -- https://code.launchpad.net/~zorba-coders/zorba/feature-mem_size/+merge/114764 Your team Zorba Coders is subscribed to branch lp:zorba. -- Mailing list: https://launchpad.net/~zorba-coders Post to : [email protected] Unsubscribe : https://launchpad.net/~zorba-coders More help : https://help.launchpad.net/ListHelp
