Re: [Boost-users] Visual Studio 2005 ptr_list visualizer?

3 Aug 2007

      ...
-----Original Message-----
From: boost-users-bounces@lists.boost.org [mailto:boost-users-
bounces@lists.boost.org] On Behalf Of Filip Konvicka
Sent: Thursday, August 02, 2007 6:44 PM
To: boost-users@lists.boost.org
Subject: Re: [Boost-users] Visual Studio 2005 ptr_list visualizer?
Hi Bill,
(please don't top post, thanks!)
...
I have written visualizers for the other pointer containers, but realize
that I had forgotten about ptr_list. I previously posted the visualizer
code
for ptr_vector, ptr_map, ptr_multimap, ptr_set, ptr_multiset, and also
array. If you don't have it I can easily post it again.
Thanks for sharing your work! Once the wiki + repository are ready,
people will hopefully find things more easily.
...
I took a quick stab at ptr_list, but I think I may have run into a
limitation (or bug) in the visualizer. It's not letting me cast the
final
expression to the templated parameter. I tried it with a direct cast and
that worked, but it seems to lose the template information in the
resulting
expression.
The problem is in the expression ($T1*)$e._Myval. It seems that $T1 (the
template parameter) is not valid at this point. If, for example the list
is
defined as ptr_list<int>, then the expression (int*)$e._Myval will work,
but
obviously we can't hard code that here. Any one have any ideas here?
Yes, this is a bit tricky... the problem is not $T1 being invalid in the
context, it rather is in how pattern matching works. I suspect that the
rule pattern matching is string-based. In this case, it is useful to
look (via a watch) at the exact type being matched. In the case of
ptr_list<int>, it is
boost::ptr_list
...
which apparently matches your filter
boost::ptr_list<*>
since you see some effects in the watch window. Hence $T1 =
"int,boost::heap_clone_allocator,std::allocator", which does not
make sense after substitution. So, to fix your rule, it suffices to
rewrite the pattern as
boost::ptr_list<*,*,*>
(in fact, boost::ptr_list<*,*> would work as well, justifying my above
guess...but it is clearly not as clean).
Cheers,
Filip
You're right. That fixed it. I should've realized. I actually had that in my
ptr_vector implementation - at least defined as ptr_vector<*,*>. Yes,
ptr_list<*,*> works as well. By the way, it turns out that the iterators
were already done. They use the same ones that ptr_vector used, so they were
working already.

I just realized that the visualizers I posted previously are all for boost
version 1.33. It's quite possible that they will fully apply to v1.34.
Though there may be an issue with ptr_map and ptr_multimap given that the
usage has changed.

I'm not in a position where I can switch over to 1.34 just yet. Can you give
that one a try and see how it fares?

I'm guessing that not using <*,*,*> instead of just <*,*> would fail if
using a custom allocator, right? I haven't the need for that yet, but it
sounds like a good reason to adjust everything to match.

Updated visualizer:

;---------------------------------------------------------------------------
;  boost::ptr_list
;---------------------------------------------------------------------------

boost::ptr_list<*,*,*>{

	children
	(
		#list
		(
			head : ($c.c_._Myhead->_Next),
			size : $c.c_._Mysize, 
			next : _Next
		) : ($T1*)$e._Myval
	)

	preview
	(
		#(
			"[", 
			$e._Mysize, 
			"](", 

			#list
			(
				head : $c.c_._Myhead->_Next,
				size : $c.c_._Mysize, 
				next : _Next
			) : ($T1*)$e._Myval,

			")"
		)
	)			      
}

-- Bill --

Re: [Boost-users] Visual Studio 2005 ptr_list visualizer?

Bill Buklis