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virtual function templates
by strasser＠uni-bremen.de 24 Feb '10

24 Feb '10

Hi, is there interest in a boost utility to implement (pseudo-) virtual function templates? real virtual function templates are obviously not possible without a JIT-compiler, but if all derived types are known to the base type, something like the following is. I've used a non-generic form of this a couple of times: struct base : enable_vtemplate<derived1,derived2>{ template<class OutputIterator> void f(OutputIterator it){ BOOST_VTEMPLATE(f,(OutputIterator),(it)); it << "not overridden\n"; } BOOST_SUPPORT_VTEMPLATE(); }; struct derived1 : base{ template<class OutputIterator> void f(OutputIterator it){ it << "derived1\n"; } BOOST_SUPPORT_VTEMPLATE(); }; struct derived2 : base{ template<class OutputIterator> void f(OutputIterator it){ it << "derived2\n"; } BOOST_SUPPORT_VTEMPLATE(); }; the runtime overhead besides the virtual call is one switch().

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shortest path between vertex A and B
by Alexandre de Morais Amory 24 Feb '10

24 Feb '10

Hi, I am starting to use BGL. I manage to read/write in dot format, add few attribs, etc. my next task is to get the set of vertex in the shortest path between vertex A and B. In a graph like this: a - b b - c c - d assuming 'a' and 'c', the result would be {a,b,c}. I know it sounds silly, but most similar examples I could find are much more complex than this. I guess breadth_first_search would solve the problem, but I am having trouble with the visitor concept... how to implement a visitor to get the set of vertex in the path between two points. Other features of the problem: I am assuming an undirected graph. all edges have unitary distances. If there are multiple shortest paths between A and B, any of the valid solutions can be returned. thanks in advance for any clue ! Regards, Alexandre Amory

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[thread] compile errors on Sandia-intel-10.1/11.0/11.1
by Emil Dotchevski 23 Feb '10

23 Feb '10

The error below is detected building a couple of Boost Exception tests that use Boost Thread. Thanks Noel and Steven for helping diagnose the problem. "/opt/intel/Compiler/11.1/067/bin/intel64/icpc" -xc++ -w1 -O0 -g -inline-level=0 -vec-report0 -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -I".." -c -o "/Volumes/Scratch/kbelco/boost/results/boost/bin.v2/libs/thread/build/intel-darwin-11.1/debug/link-static/threading-multi/pthread/thread.o" "../libs/thread/src/pthread/thread.cpp" ../libs/thread/src/pthread/thread.cpp(385): error: identifier "get_nprocs" is undefined return get_nprocs(); ^ Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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[Regex & ICU] boost::regex & icu compilation warnings: missing #pragma pack(pop)
by Henry Tan 23 Feb '10

23 Feb '10

Wondering if this is a known issue and there is a solution to fix this build warning when you are compiling boost::regex with ICU library. >warnings in directory d:\ >d:\boost_1_41\boost\regex\v4\u32regex_iterator.hpp(25) : warning C4103: 'd:\boost_1_41\boost\regex\v4\u32regex_iterator.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) >d:\boost_1_41\boost\regex\v4\u32regex_iterator.hpp(187) : warning C4103: 'd:\boost_1_41\boost\regex\v4\u32regex_iterator.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) >d:\boost_1_41\boost\regex\v4\u32regex_token_iterator.hpp(38) : warning C4103: 'd:\boost_1_41\boost\regex\v4\u32regex_token_iterator.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) >d:\boost_1_41\boost\regex\v4\u32regex_token_iterator.hpp(368) : warning C4103: 'd:\boost_1_41\boost\regex\v4\u32regex_token_iterator.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) Cheers, HT

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[exception] help needed diagnosing Sandia-intel-10.1/11.0/11.1 failures
by Emil Dotchevski 23 Feb '10

23 Feb '10

See the following logs, which seem identical, and it isn't clear to me what's wrong: http://tinyurl.com/yzjo8v4 http://tinyurl.com/ygooqj7 http://tinyurl.com/yjp3n68 Ideas? Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode

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[thread][config] VC10RC fails compiling when using thread library (BOOST_NO_RVALUE_REFERENCES)
by Hartmut Kaiser 23 Feb '10

23 Feb '10

Hey all, the new 'un-definition' of BOOST_NO_RVALUE_REFERENCES for VC10 breaks compilation of code using the thread library. Is it a problem of VC10 or the thread library? Regards Hartmut --------------- Meet me at BoostCon www.boostcon.com

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Re: [boost] Boost Graph library - r_c_shortest_paths
by Andrew Sutton 23 Feb '10

23 Feb '10

> I checked the files I sent you and they were the correct versions (all > three code files: the test file, the example file, and > r_c_shortest_paths.hpp). The test and example files both run without any > problems on my system (WIN XP 32 SP 3, MS Visual C++ 2008). > I've finally had some time to go through the resubmission. There are/were a number of issues that need to be addressed. First, property maps, functors, and visitors are virtually always passed by value. If those objects need to maintain complex state between calls, it's typically done by building a functor (visitor, etc) that has a reference to an external state object. I fixed this. Second, I removed the ks_smart_ptr class, which turned out to be not very smart. It only wrapped the pointer, but didn't manage it in any way. I also cleaned up some of the allocation/deallocation code by moving the calls to two new functions create and destroy. Inidentally, valgrind shows that this implementation leaks memory. I put cout's in create and destroy to count allocations and deletions (16646 allocs to 15994 deallocs). My guess is that one of the rarer code paths in the dispatch doesn't actually delete. This needs to be investigated. Third... just a style point... some of the identifiers are a little long. I think the readability could be improved by shortening them. Fourth, and I'm hoping to get Jeremiah's input on this... I'm not a fan of passing vector<vector<>>& or vector<>& as top-level parameters. It might be better to require a template parameter that is essentially a matrix- or vector-like object. That would simplify the call interface and allow a little more freedom w.r.t. parameter types. Thoughts? Fifth... and Final... The interface to the algorithm is changing which can break backwards compatibility. Maybe we need to give the new module a different name. Thoughts? Here's a tarball with the code ready to be dropped into Boost. You should refer to this version since its what I'm going to be merging. http://www.cs.kent.edu/~asutton/rcsp.tar.bz2 Andrew Sutton andrew.n.sutton(a)gmail.com

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Re: [boost] [msm] scalability
by Christophe Henry 22 Feb '10

22 Feb '10

David Abrahams wrote: > The idea would be to do all parts that are “hard on the compiler” > at runtime. I don't see why you should have to sacrifice features. I promised to make an analysis of which feature costs how much compile-time and test your point. I hope to bring a beginning of an answer and hope you will enjoy the trip to VC++ world ;-) I took the iPod example from the last BoostCon and compile it with VC8 and VC9 in Debug and Release. I think it is an interesting example: submachines, orthogonal regions, a good number of states. I also took the MPLLimitTest example (80 transitions, 80 states) to check a wide state machine not factored into any submachines. Both can be found in the sandbox in libs/msm/doc (/iPod or directly for the MPLLimitTest). So, the results: VC9 (Release): 60s VC9(Debug): 79s VC8(Release): 64s VC8(Debug): 183s (!!!) Notice how debug takes so much longer, as rightly noticed by Jeff. Part1: we now move the submachines into different headers, simply included in the main application. Should change nothing, right? First small surprise, it helps VC8 in Debug: VC9 (Release): 65s VC9(Debug): 80s VC8(Release): 68s VC8(Debug): 166s I didn't see why Debug took so much longer, so I played a bit with the compiler options until I found the culprit. If we now deactivate the /Gm option ("Enable minimal rebuild") in Debug (not activated in Release), we now see a big difference: VC9(Debug): 58s VC8(Debug): 62s Waow! 20s better for VC9, 102 for VC8. This could explain Jeff's problems. This is what I call a successful optimization from the compiler to create a minimal rebuild. Now Debug builds are faster than Release (due to shorter link time if you ask). Part2: This is nice but we did not add any new policy for faster compiling yet. I now add one. Unfortunately, reducing the number of template instantiations proved to be a hard business as most of removed instantiations which were "hard on the compiler" were still done somewhere else and VC is clever enough not to repeat itself. On the MPLLimitTest it gives: Before: VC9(Release): 134s VC9(Debug): 135s (without /Gm. Otherwise count 275!) VC8(Release): crash :( (ok this is really a hard test) VC8(Debug): I stopped after the compiler used up 3,5GB of my 4GB... after: VC9(Release): 84s VC9(Debug): 84s VC8(Release): crash :( VC8(Debug): 153s Ok better. It can be also better for the iPod example as the policy allows you to move some of the metaprogramming for submachines to other TUs and compile with 3 cores (one fsm, 2 submachines) using /MP (available on VC8 and VC9). See in the doc the example in iPod/Part2. We now have the following compile time (using 3 cores): VC9(Release): 44s VC9(Debug): 37s VC8(Release): 50s VC8(Debug):40s This looks much better as it allows the clever user to build submachines and enjoy better compile times. For cases where performance is needed, simply omit the submachines' cpp files from build. The trick works using a boost::any to contain the event, thus allowing you to avoid instantiating a process_event inside the main machine process_event. The only feature you lose with this policy is the new possibility to make a derived event fire his basis event's transition (any can recognize only strict types). So this is the current state. But it can be better. We still pay for the instantiation of submachines into the main machine, which still costs you time. I made a test using a proxy for submachines. The proxy containing only a void* to the real submachine, instantiating it is cheap. It's not finished but we now build on 5 cores (the main fsm, 2 for each submachine, 2 submachines). Yes we can now build a submachine on 2 cores :) This gives us the possible future compile-time: VC9(Release): 34s VC9(Debug): 27s VC8(Release): 40s VC8(Debug):30s I hope this will make the compile-time problem more manageable. Again, more to come on this later. Jeff, if you could give it a try, it would be really great! Christophe PS: I am using a Q6600, 4 cores, 2.4GHz, no hyperthreading. We can soon use the new hexacore with hyperthreading :)

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[geometry] Documentation prototype for review
by Mateusz Loskot 22 Feb '10

22 Feb '10

Hi, I'm working on documentation of Boost Geometry based on Quickbook and I've prepared a prototype: http://mateusz.loskot.net/tmp/ggl/qbk/ What I'm doing is manually porting the content from Doxygen-based (http://geometrylibrary.geodan.nl/) plus restructuring, reformatting and completing it with missing details. I'd like to ask everyone who is interested in Boost Geometry library for comments, impressions and suggestions of improvements. Note, nodes marked with (?) are not finished and empty, but included to give impression about the overall structure. I'd be especially interested comments about the structure, if it's accessible to new users and usable for advanced users at the same time. The Reference is one of the most important section I'd like to master, so please share your comments on the form and completeness of the concepts specification, for example: http://mateusz.loskot.net/tmp/ggl/qbk/geometry/reference/geometries/concept… types description, for example: http://mateusz.loskot.net/tmp/ggl/qbk/geometry/reference/geometries/types/p… and functions description: http://mateusz.loskot.net/tmp/ggl/qbk/geometry/reference/arithmetic/add_poi… Thanks in advance for your feedback. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org

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[build] summary at end
by Vladimir Prus 22 Feb '10

22 Feb '10

FYI, Previously, I've made the build process to print information as to where the headers and libraries are to be found. However, that was printed at the start of the build, and many used missed that. I've now checked in a patch to print the message at the end of the build (if there are no errors). You need trunk bjam for this to work. Older bjam will not print that message but otherwise work. The sample wording is as follows: The Boost C++ Libraries were successfully built! The following directory should be added to compiler include paths: /home/ghost/Work/Boost/boost-svn The following directory should be added to linker library paths: /home/ghost/Work/Boost/boost-svn/stage/lib Comments are appreciated, -- Vladimir Prus http://vladimir_prus.blogspot.com Boost.Build: http://boost.org/boost-build2

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