Re: [Boost-users] [multi_index] MSVS 2005 visualizers?

Hello Filip, I did reply this email last Thursday, I guess somehow it didn't make it to your inbox (??) I'm copying and pasting my answer here again: Filip Konvi?ka ha escrito:

Joaquín Mª López Muñoz (23.5.2007 18:16):

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Hello Filip,

I know nothing about VS visualizers so I'm afraid I can't help much on that part, but feel free to ask as much as you need on the internal structures of B.MI --publicly of privately if you feel this is going to be a long list of mails. [I tried replying to your email address, but I don't know whether this ever reached you, so I retry here...]

I tried some debugging with multi_index_container > >, which is probably the simplest case. I ended up in the "space" member of "pod_value_holder", which seems to handle some alignment issues and from the name I guess it should also contain the data, but I don't see it in the debugger.

That "space" member is used as raw storage upon which the value (of type int in this case) is constructed. So, you have to reinterpret_cast to get to your value. Does the visualizer allow you to do that?

As for sequenced_index_node_impl, this shows both _prior and _next, but does not expose node data. See the attached snapshot. Do you have an idea how could I see the one int that I inserted into the container?

Nodes of a multi-index container consist of several base classes each providing some part of the whole: the value (index_node_base) and pointers for each of the indices (one sequenced_index_node_impl in this case, as there is only one sequenced index.) In schematic form, the node you're deaing with now has the following structure: struct index_node_base { int value; }; struct sequenced_index_node_impl { sequenced_index_node_impl* prior_; sequenced_index_node_impl* next_; } struct node_type: public index_node_base, public sequenced_index_node_impl { }; So when you navigate through the sequenced index using prior_ and next_ pointers, you've got to down cast to node_type to get to the values. Is it clear (more or less)? Joaquín M López Muñoz Telefónica, Investigación y Desarrollo