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Boost.Containers? (WAS Re: Proposal: Monotonic Containers - Comparison with boost::pool, boost::fast_pool and TBB)
by Dean Michael Berris 24 Jun '09

24 Jun '09

On Wed, Jun 24, 2009 at 10:40 AM, Christian Schladetsch<christian.schladetsch(a)gmail.com> wrote: > > What do people think of moving boost::interprocess::containers to > boost::containers? These containers are not really specific to interprocess? > I think this can easily be done through 'using' declarations: namespace boost { namespace containers { using boost::interprocess::list; using boost::interprocess::vector; /* ... */ } } I don't think it should move though to support earlier applications that are already using the interprocess namespace for the containers. -- Dean Michael Berris | Software Engineer, Friendster, Inc. blog.cplusplus-soup.com | twitter.com/mikhailberis | linkedin.com/in/mikhailberis | profiles.friendster.com/mikhailberis | deanberris.com

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[range][rangex] Joining two unrelated ranges?
by Dean Michael Berris 24 Jun '09

24 Jun '09

Hi Guys, I was wondering if a utility that allows the encapsulation (and merging) of two ranges is already part of RangeEx? I was thinking along the lines of: vector<int> a, b; // populate a, populate b auto r = concat(a, b); // concatenates the ranges into a single range set<int> c(begin(r), end(r)); // r looks like a single forward range I'm not sure if this is already supported in Boost.Range and it'd be nice to know if this is already in RangeEx. TIA -- Dean Michael Berris | Software Engineer, Friendster, Inc. blog.cplusplus-soup.com | twitter.com/mikhailberis | linkedin.com/in/mikhailberis | profiles.friendster.com/mikhailberis | deanberris.com

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boost::compressed_bitset
by Zachary Turner 24 Jun '09

24 Jun '09

I know there's over a zillion bitset implementations, but often times I have found myself in need of a bitset that is efficient (space-wise) at storing millions, billions, or even trillions (no joke) of bits. For this I have developed an in-house class which stores bits in a structure vaguely reminiscent of a "T-Tree" (http://en.wikipedia.org/wiki/T_tree) You can think of it basically as an std::map<boost::uint64_t, boost::uint64_t> where <key, value> represents the *interval* of bits [key, key+value-1]. So it's basically run-length encoded, with logarithmic lookups instead of linear lookups. Obviously the worst case scenario is where bits alternate 10101... throughout the entire bitset, and this structure will be terrible in that case. But where there are frequent runs of 0 and 1 bits, this gives orders of magnitude savings in space. Since a map is sorted on key, it's still a valid binary search tree and one can find the node for the k'th bit by map::lower_bound(k) and quickly check whether the bit is set by testing whether k is in [iter->first , iter->first+iter->second). The most difficult part is insertion / deletion since it involves splitting (or merging) intervals and rebalancing but the complexity is still no worse than that of a normal rebalancing avl tree. I almost exclusively use this structure in a way that interval nodes represent sequences of 1 bits, but it can just as easily be used the other way around, where intervals represent sequences of 0 bits. In fact now that I think about it probably doesn't even matter. Performing bitwise operations on such a structure is very fast. All you need to do is expand / reduce the intervals appropriately. Lookup / assignment is obviously not constant time but of course that is the tradeoff. Forward / reverse iteration is still very fast however as you only need to take the non-constant time hit once on begin(). It is also very fast to iterate only 1 bits or only 0 bits for the same reason, which can be quite slow with normal bitsets. The implementation I currently have is very unsuitable for boost for many reasons, but if there is enough interest I will (slowly) work on adapting this to be more generic / usable by a wider audience, of course with suggestions and input from the community. Zach

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Re: [boost] version conflicts: is there a solution?
by Artyom 24 Jun '09

24 Jun '09

Hi, Take a look on this namespace renaming script: http://lists.boost.org/Archives/boost/2009/05/151816.php It should work, not sure about correctness of build system. I consider to submit it officially once it polished, but it seems to work. Artyom --- On Wed, 6/24/09, Lewis Hyatt <lhyatt(a)gmail.com> wrote: > From: Lewis Hyatt <lhyatt(a)gmail.com> > Subject: [boost] version conflicts: is there a solution? > To: boost(a)lists.boost.org > Date: Wednesday, June 24, 2009, 3:49 AM > Hi Everyone- > > This has been discussed before > (http://thread.gmane.org/gmane.comp.lib.boost.devel/180008) > but I think my > question is along a slightly different line so I thought I > would ask about it. > Let's say I want to compile and distribute a library > (without the source), and I > happen to use some boost header-only libraries as an > implementation detail in > some of my functions. None of the headers associated with > my library include > boost headers; it's purely an internal detail. > > Now, it seems to me that users of my library will still > have to be aware of the > fact that I used boost in my implementation -- > specifically, if they happen to > use different versions of the same boost libraries in their > code, then the ODR > is violated and the behavior is undefined. > > I realize this isn't a boost-specific problem (it would > affect any library of > template functions), but I am wondering if there is a > boost-specific solution > already worked out? Has anyone thought about this? It seems > to me that in this > case, what would be ideal would be if I could do: > > #define BOOST_NAMESPACE some_unique_namespace_for_boost > #include "boost/algorithm/string.hpp" > BOOST_NAMESPACE::shared_ptr<void> x; //or whatever > > Then I can insure there are no ODR violations and I don't > need to bother users > of my library with the fact that I used boost at all. > > Other than the sheer annoyance of having to go through all > the boost code to use > this macro, is there a strong downside to this approach? > > Alternatively, I could try: > > namespace { > #include "boost/..." > } > > But I don't know, could this work? Or are there boost > headers that rely on fully > qualified references like ::boost::algorithm::whatever? > > I'd appreciate anyone's thoughts on this issue, thanks! > > -Lewis > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost >

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Re: [boost] Proposal: Monotonic Containers - Comparison with boost::pool, boost::fast_pool and TBB
by Christian Schladetsch 24 Jun '09

24 Jun '09

> Updated tests (more of them, better formatting of results) for > https://svn.boost.org/svn/boost/sandbox/monotonic/libs/monotonic/test/compa… here > http://tinyurl.com/m83vll for GCC and here http://tinyurl.com/n9g8jv for > MSVC. I also added a column for std::allocator/mono. Have added comparison against TBB, as requested. These results are at the same location as linked to above. Christian.

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Re: [boost] boost namespace
by Artyom 24 Jun '09

24 Jun '09

> I need to use two versions of boost in my > application. One the libs I link > against is statically linked against boost 1.34 and I'd > like to use 1.35's > asio library. First of all Asio comes as stand alone library outside of boost namespace. So, you may just use it as is or use namespace renaming: #ifdef USE_BOOST_ASIO #include <boost/asio.hpp> namespace netio = boost::asio; using boost::system::error_code; using boost::system::system_error; #else #include <asio.hpp> namespace netio = asio; using asio::error_code; using asio::system_error; #endif And then just relate to netio::... so you would keep an ability to upgrade to boost asio in future. This is the way I build CppCMS http://cppcms.sourceforge.net/ conditionally using Boost 1.33.1 and Asio or boost 1.35 and above only. > I believe I can make both versions > co-exist if I can manage > to rename boost 1.35's namespace to something like > boost135. > Take a look on a script I had written once: http://lists.boost.org/boost-build/2009/05/21911.php But note! boost 1.35 and 1.34 are not compatible nither ABI nor API. So you **must** not mix them in same module! This may be very tricky. So you can't use boost in interfaces between modules that use different versions of boost. Artyom

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[Review Request] polygon
by Simonson, Lucanus J 23 Jun '09

23 Jun '09

Gtl was renamed to boost::polygon. The source is available at https://svn.boost.org/svn/boost/sandbox/gtl/boost/polygon/ And the documentation is at https://svn.boost.org/svn/boost/sandbox/gtl/doc/index.htm I have a review manager and a number of prospective reviewers lined up, so we should be able to at least get the review started smoothly. I would like the review wizard to contact me off list to discuss which dates are more suitable to have the review given my personal schedule. Thanks, Luke

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SafeInt code proposal
by Omer Katz 23 Jun '09

23 Jun '09

A friend and I have started working on a SafeInt library which we hope will be included in Boost the library is composed of a template class, which excepts existing integer types as a parameter, and an exception class. not all operators have been implemented and there is still work to be done on the library, but we have reached a stage in which at least the basic operators are ready and tested. I've attached to this thread a zip file containing the code for the library and a tester we wrote (as an example for how the class should be used) I've also uploaded it to the boost vault. We would appreciate it if you took the time to review our code and give us your comments, tips and opinions (either as a reply to this thread or by email - omerktz(a)gmail.com) thanks, Omer Katz and Zil Levi

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[task] boost.task-0.2
by k-oli＠gmx.de 23 Jun '09

23 Jun '09

Hi, I've uploaded a new version of boost.task (boost.threadpool) to boost vault http://www.boost-consulting.com/vault/index.php?directory=Concurrent Programming Changes: - detail/atomic.hpp with atomic_exchange (gcc + x86|ppc) - handle< R > with new function get_future() returning reference to internal shared future - moved execution-policies new_thread, own_thread and as_sub_task in separat headers - async() with as_sub_task as default execution-policy - functions interrupt_and_wait_until() and interrupt_and_wait_for() from handle< R > returning boolean indicating if op. succeeded or timed out - move semantics for task< R > and static_pool< R > - new function interrupt_all_worker() for static_pool< Channel > in order to interrupt all worker-threads without invalidating the pool - default_pool() removed because thread_resource_error exceptions thrown by static pool - support of processor-binding for FreeBSD (>=7.1) - tests updated - examples updated - documentation updated regards, Oliver

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How to speed up the djikstra graph
by Lennart Berg 23 Jun '09

23 Jun '09

Hi Everybody I have had the pleasure of using the boost graph library for my project now, but I have ran into some problems, that I hope you can guide me on. First of all, let me tell a little about the project. I am a third party developer for paradox interactive, making an expansion for one of their games. Now i have implemented the djikstra alghorithm to simulate the transport capacity of countries, and it works pretty well. However I still think that the speeds to be improved somewhat (takes about 1-2 secs to compute), to make it more playable. First of all the map consists of ~2500 provinces / vertexes each with 4-8 edges / neighbours. I Find all the provinces I can access and then add all neighbours from it as edges. Each edge is allocated a cost according to infrastructure, terrain and distance from orgin to destination. Each "round" of the game is an hour, so a day is effectively 24 rounds. Right now I make a new graph once every day, one separate graph for each country, and compute it for every country once a day. However as the game has up to 300+ countries that becomes a pretty harsh computational burden. Now pretty much every variable in this setup can change hourly. ( location of units, conquest / loss of provinces, destruction of infrastructure, expansion / repair of infrastructure) So the question is how I can improve this approach. Optimally the graph should be persistant and allow me to dynamically add / remove provinces and change the cost of the edges every hour (as I understand it the boost library allows that right now with vertex_clear / add etc.), and giving new values without recomputing every single edge in the graph 300 times every hour. Is that possible? And if how would that be done? Thanks in advance Lennart Berg

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