March 2010 - Boost-users - lists.preview.boost.org

Problems with copying view on mpl set on solaris compiler.
by Jonathan Chambers` 22 Mar '10

22 Mar '10

I'm trying to get the following to compile on solaris using S1S12u1; #include <boost/mpl/copy.hpp> #include <boost/mpl/set.hpp> #include <boost/type_traits.hpp> #include <boost/mpl/placeholders.hpp> #include <boost/mpl/inserter.hpp> #include <boost/mpl/insert.hpp> #include <boost/mpl/filter_view.hpp> typedef boost::mpl::copy< boost::mpl::filter_view< boost::mpl::set<int>, boost::is_same<boost::mpl::_, int> >, boost::mpl::inserter< boost::mpl::set<>, boost::mpl::insert<boost::mpl::_, boost::mpl::_> > >::type type; template <class undefined> struct Debug; Debug<type> debug; int main(int argc, char *argv[]) { return 0; } and I get the following compiler errors "boost_1_42_0/boost/mpl/aux_/filter_iter.hpp", line 66: Error: Redefining boost::mpl::next<boost::mpl::T> after use in boost::mpl::aux::filter_i ter<boost::mpl::s_iter<boost::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_ ::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::s_item<int, boost::mpl::set0<mpl_::na>>>, boo st::mpl::s_iter<boost::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, m pl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::protect<boost::mpl::bin d2<boost::mpl::quote2<boost::is_same<boost::T, boost::U>, mpl_::void_>, mpl_::arg<-1>, int>, 0>>. "boost_1_42_0/boost/mpl/next_prior.hpp", line 31: Where: While specializing "boost::mpl::aux::filter_iter<boost::mpl::s_iter<boost::mpl::set <int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mp l_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::s_item<int, boost::mpl::set0<mpl_::na>>>, boost::mpl::s_iter<boost::mpl::set<int, c har, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::protect<boost::mpl::bind2<boost::mpl::quote2<boost::is_same<b oost::T, boost::U>, mpl_::void_>, mpl_::arg<-1>, int>, 0>>". "boost_1_42_0/boost/mpl/next_prior.hpp", line 31: Where: Specialized in boost::mpl::next<boost::mpl::aux::filter_iter<boost::mpl::s_iter<boo st::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::s_item<int, boost::mpl::set0<mpl_::na>>>, boost::mpl::s_iter<boost::mpl ::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::n a, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::protect<boost::mpl::bind2<boost::mpl::quote2<boos t::is_same<boost::T, boost::U>, mpl_::void_>, mpl_::arg<-1>, int>, 0>>>. "boost_1_42_0/boost/mpl/aux_/preprocessed/plain/fold_impl.hpp", line 162: Where: Specialized in boost::mpl::aux::fold_impl<-1, boost::mpl::a ux::filter_iter<boost::mpl::s_iter<boost::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mp l_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::s_item<int, boost::mpl::set0<mpl_ ::na>>>, boost::mpl::s_iter<boost::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::protect<boo st::mpl::bind2<boost::mpl::quote2<boost::is_same<boost::T, boost::U>, mpl_::void_>, mpl_::arg<-1>, int>, 0>>, boost::mpl::aux::filter_iter<boost ::mpl::s_iter<boost::mpl::set<int, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl _::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::s_iter<boost::mpl::set<in t, char, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_: :na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::mpl::set0<mpl_::na>>, boost::mpl::protect<boost::mpl::bind2<boost::mpl::quote2<boost::is_sa me<boost::T, boost::U>, mpl_::void_>, mpl_::arg<-1>, int>, 0>>, boost::mpl::set<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_ ::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost:: mpl::insert<mpl_::arg<-1>, mpl_::arg<-1>, mpl_::na>>. "boost_1_42_0/boost/mpl/fold.hpp", line 39: Where: Specialized in boost::mpl::fold<boost::mpl::filter_view<boost::mpl::set<int, char, mpl_:: na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::is_same<mpl_::arg<-1>, int>>, boost::mpl::set<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boo st::mpl::insert<mpl_::arg<-1>, mpl_::arg<-1>, mpl_::na>>. "boost_1_42_0/boost/mpl/copy.hpp", line 36: Where: Specialized in boost::mpl::aux::copy_impl<boost::mpl::filter_view<boost::mpl::set<int, ch ar, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::is_same<mpl_::arg<-1>, int>>, boost::mpl::inserter<boost::mpl::set<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl _::na, mpl_::na, mpl_::na>, boost::mpl::insert<mpl_::arg<-1>, mpl_::arg<-1>, mpl_::na>>>. "boost_1_42_0/boost/mpl/copy.hpp", line 54: Where: Specialized in boost::mpl::copy<boost::mpl::filter_view<boost::mpl::set<int, char, mpl_:: na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::is_same<mpl_::arg<-1>, int>>, boost::mpl::inserter<boost::mpl::set<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl _::na, mpl_::na>, boost::mpl::insert<mpl_::arg<-1>, mpl_::arg<-1>, mpl_::na>>>. "filter_view.cpp", line 19: Where: Specialized in non-template code. "filter_view.cpp", line 24: Error: In this declaration "debug" is of an incomplete type "Debug<boost::mpl::s_item<int, boost::mpl::set0<mpl_::na >>>". 2 Error(s) detected. You can see by the debug that the program has managed to deduce the correct type, even though it errored. On GCC-4.1.1 this gives filter_view.cpp:24: error: aggregate 'Debug<boost::mpl::s_item<int, boost::mpl::set0<mpl_::na> > > debug' has incomplete type and cannot be defined Which is exactly what I want. Anyone else had these issues, found workarounds, etc? This problem also occurs with boost::mpl::transform_view, but appears to work for boost::mpl::joint_view. Any help appreciated. Jon. _________________________________________________________________ Send us your Hotmail stories and be featured in our newsletter http://clk.atdmt.com/UKM/go/195013117/direct/01/

1 0

blocking read after async connect
by David Kaplan 22 Mar '10

22 Mar '10

I have a class that performs a timed connect (i.e. using an async connect that returns an error if connection failed/timed-out). However every asio::read/write performed on the socket after a successful async_connect fails. Any ideas? Is it impossible to perform read/write on such a socket? do I have to stop() the io service to put it back into synchronous mode?

2 3

[fusion?] [Phoenix?] Calling arbitrary method with collection of args
by Nat Goodspeed 22 Mar '10

22 Mar '10

We have a data type equivalent to a recursive variant that can hold a few scalar types or a vector of such types. My colleague proposes that we build a template function that will accept a free function or class method (that is, any callable whose signature we can infer) plus a vector of the variant type. For each formal parameter type in the callable's signature, this function would ensure that the vector is long enough to fill it, and then that the runtime type of the appropriate vector entry is compatible with the static type of the parameter. Finally it would call the callable, filling the formal parameters from the variant vector. I strongly suspect that this function already exists in Boost. I simply don't know which library to research. (OvermindDL1?)

3 7

undefined reference to `boost::program_options
by G.NAGENDAR 22 Mar '10

22 Mar '10

Hi, When i run my C++ program which is using boost library, i am getting these errors main.o: In function `boost::program_options::variables_map::operator[](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const': /usr/local/include/boost-1_35/boost/program_options/variables_map.hpp:161: undefined reference to `boost::program_options::abstract_variables_map::operator[](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' /usr/local/include/boost-1_35/boost/program_options/variables_map.hpp:161: undefined reference to `boost::program_options::abstract_variables_map::operator[](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' /usr/local/include/boost-1_35/boost/program_options/variables_map.hpp:161: undefined reference to `boost::program_options::abstract_variables_map::operator[](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' /usr/local/include/boost-1_35/boost/program_options/variables_map.hpp:161: undefined reference to `boost::program_options::abstract_variables_map::operator[](std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const Please help to solve this problem. Please... -- Thanks & Regards Nagendar

2 2

Variant and Fusion
by Matthias Vallentin 21 Mar '10

21 Mar '10

Hi, there used to be a variant adapter for fusion sequences, but it has been rightfully removed: on Wed Dec 19 2007, Joel de Guzman <joel-AT-boost-consulting.com> wrote: > I intend to remove the variant adapter from fusion. After thorough > investigation, I think now that the move to make variant a > fusion sequence is rather quirky. A variant will always > have a size==1 regardless of the number of types it can contain > and there's no way to know at compile time what it contains. > Iterating over its types is simply wrong. All these imply that > the variant is *not* a fusion sequence. Let's say I have a recursive variant and would like to flatten the variant to create some sort of heterogeneous sequence from it. Particularly, I would like to chop the variant into multiple disjunct Fusion sequences, each of which are handed to generic component that operates with Fusion sequences. The above suggests that Fusion is not the right tool. What would be a better approach to handle this problem? Should I split the variant into smaller variants instead? What made Fusion so attractive is the notion of tiers, i.e., light-weight views of references to the actual data. Is there a variant equivalent of tiers? Matthias -- Matthias Vallentin vallentin(a)icsi.berkeley.edu http://www.icir.org/matthias

2 6

Multithread event handling
by Alessandro Bellina 21 Mar '10

21 Mar '10

Hello boost, Traditionally, I think of services as having a thread pool or manually managed threads to handle requests and produce responses. I have been looking at boost::asio and tbb as an alternative to this in order to take advantage of multiple cores. Also, I think that implementing an event handler with asio or tbb should provide better performance over a threadpool. Do you have any suggestions? So far, I have implemented an example using tbb::task_group and spawned tasks. This yielded full CPU utilization, but since these are very short lived tasks, the task creation overhead took over. Using io_service, it seems to be as easy as posting to the service, and running it among different threads. Would this be the correct approach for my case? Can somebody share their experiences on libraries or patterns used to implement an event handling mechanism? Thanks, Alessandro

4 5

Possibly too newbie a question?
by Eric Whitcombe 20 Mar '10

20 Mar '10

I haven't received any response to my question. If this is is not the appropriate forum I would appreciate some suggestions as to where to ask the question. I have gone over the mailing list groups page and this seems to be the place to ask it but I could be wrong. I am stepping through interprocess shared memory code and I was a little confused by the offset_ptr code that I was hitting*. I cannot figure out how that is specified to the template of rbtree_best_fit. I see in boost/interprocess/interprocess_fwd.hpp the declaration of managed_shared_memory by typedef'ing basic_managed_shared_memory with rbtree_best_fit<mutex_family> as the AllocationAlgorithm argument but I can't figure out how offset_ptr is is supplied as the VoidPointer argument to the rbtree_best_fit template. That template has 3 arguments but the forward declaration only provides one. Are the other two somehow inferred? If so, how? * I have looked at the documentation for interprocess - including the explanation of offset_ptr. I understand the need for it. I just don't see how it is incorporated into the rbtree_best_fit template.

3 7

Re: [Boost-users] setup question
by Rick Boesch 20 Mar '10

20 Mar '10

Steven, many thanks. I tried your suggestion and was able to verify exactly what I needed to know. It seems "bjam -help" says -n will not execute the updating actions, but it says nothing about printing commands. I didn't cross check this with the Boost web page documentation which is in fact different (and says -n will print the commands). As for the email timestamp, blackouts from storms over the last few days, and a low battery on the box I sent the email from, apparently conspired to confuse the clock. Again, thanks for your help. Rick -----Original Message----- >From: Steven Watanabe <watanabesj(a)gmail.com> >Sent: Mar 19, 2010 6:56 PM >To: boost-users(a)lists.boost.org >Subject: Re: [Boost-users] setup question > >AMDG > >Rick Boesch wrote: >> Hello all -- looking for a small bit of guidance please. I'm building a 64bit Boost library from scratch. I'm fairly sure I did almost everything correctly, but would like to check one nagging detail. My system is Windows 7, Visual Studio 2005 and I'm building for 64 bit, specifically AMD64. >> >> I believe bjam.exe built correctly because my path was set up properly for the x64 toolset and bjam.exe was deposited in the auto-generated directory BOOST_ROOT\tools\jam\src\bin.ntx86_64. To do this, I ran "build vc8" on the command line. >> >> My question concerns the use of bjam along with the "using" instruction in the ...\V2\user-config.jam file. I set the "using" instruction to be >> >> using msvc : 8.0 : cl : <setup-amd64>vcvarsall ; >> >> and my command line is >> >> bjam address-model=64 --build-dir="C:\Program Files\boost\boost_1_42_0\boost-build" --build-type=complete stage >> >> I built two different ways: >> >> 1) In a virgin cmd window -- which is not set up for 64 bit tools by default -- I ran vcvarsall manually on the command line (with no args, I set it up to default to setting up 64 bit), which sets up my 64 bit environment and which I have echo to the screen "AMD64 env" for confirmation. I confirmed I was then defaulting to the correct "cl", etc., and then executed in BOOST_ROOT the bjam command line above. I have yet to test the output, but it seemed to work. >> >> 2) In another virgin cmd window, I cd'd to BOOST_ROOT and executed ONLY the bjam command line above. According to the documentation for the "using" instruction, the batch file vcvarsall (which is in my default PATH) is supposed to be called before any tools are used, but I never saw "AMD64 env" echoed to the screen, nor to a .log file which I piped to in order to make sure I didn't miss anything. Yet, bjam created an output tree containing various "address-model-64" directories. When I checked my PATH after the build, it did not contain the paths that vcvarsall is supposed to set up. >> > >The environment setup the Boost.Build does is local to each command. > >> Question: In scenario (2) above, vcvarsall clearly did not run in my cmd session, but did bjam run it in some internally generated shell? If no, why not (did I do something incorrectly)? If yes, is this why I didn't see my echo confirmation? > >You can run bjam -a -n <other options> to see the commands that >Boost.Build actually runs. > >> So I'm wondering if I have a 64 bit build or not -- and I prefer scenario (2) to scenario (1)! >> > >In Christ, >Steven Watanabe > >P.S. The timestamp on this message was 2004. >

1 0

How to use scoped_lock
by weii 20 Mar '10

20 Mar '10

Dear all, I got a compiler(gcc 3.4.5) error while using boost.thread. The following is my code: ----------------------------------------------------------------------------------------------------------------------------- #include <boost/thread/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/bind.hpp> #include <iostream> boost::mutex io_mutex; void count(int id) { boost::mutex::scoped_lock lock(io_mutex,false); for (int i = 0; i < 10; ++i) { lock.lock(); std::cout << id << ": " << i << std::endl; lock.unlock(); } } int main(int argc, char* argv[]) { boost::thread thrd1(count, 1); boost::thread thrd2(count, 2); thrd1.join(); thrd2.join(); return 0; } ----------------------------------------------------------------------------- I know I can just abandon the lock() and unlock() function since the constructor and destructor will do them for me. But I can't understand how this error occurs and why the compiler has something to do with basic_timed_mutex. Anyone can give me some clues? Thanks in advance.

2 2

Re: [Boost-users] Building boost-1.42.0 wuth VS 2005 - precompiled header error
by john blair 19 Mar '10

19 Mar '10

Thanks for the reply Paul. So this error has been discussed earlier http://lists.boost.org/boost-build/2009/08/22231.php Removing debug-store=database does work and like original poster I too am not sure what consequences that has. --- On Sat, 3/20/10, Paul A. Bristow <pbristow(a)hetp.u-net.com> wrote: > From: Paul A. Bristow <pbristow(a)hetp.u-net.com> > Subject: Re: [Boost-users] Building boost-1.42.0 wuth VS 2005 - precompiled header error > To: boost-users(a)lists.boost.org > Date: Saturday, March 20, 2010, 12:12 AM > > -----Original Message----- > > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] > On Behalf Of john blair > > Sent: Friday, March 19, 2010 2:13 AM > > To: Boost-users(a)lists.boost.org > > Subject: [Boost-users] Building boost-1.42.0 wuth VS > 2005 - precompiled header error > > > > I am trying to build boost-1.42.0 with visual studio > 2005 and getting the following error: > > assoc_laguerre.cpp > > libs\math\build\..\src\tr1\assoc_laguerre.cpp(6) : > error C2858: command-line opt > > ion 'program database name > (/Fdc:\toolchain\src\boost-1.42.0\build-win32-vc80-de > > > bug\boost\bin.v2\libs\math\build\msvc-8.0\dbg\dbg-str-dtbs\lnk-sttc\thrd-mlt\lib > > boost_math_tr1-vc80-mt-gd-1_42.pdb)' inconsistent with > precompiled header, which > > used > '/Fdc:\toolchain\src\boost-1.42.0\boost_1_42_0\vc80.pdb' > > libs\math\build\..\src\tr1\assoc_laguerre.cpp(6) : > error C2859: c:\toolchain\src > > > \boost-1.42.0\build-win32-vc80-debug\boost\bin.v2\libs\math\build\msvc-8.0\dbg\d > > > bg-str-dtbs\lnk-sttc\thrd-mlt\libboost_math_tr1-vc80-mt-gd-1_42.pdb > is not the p > > db file that was used when this precompiled header was > created, recreate the pre > > compiled header. > > ...failed updating 1 target... > > > > Anybody knows how to resolve this? > > John Maddock is the man who can definitively answer this, > but since he hasn't replied yet, > > does the > > I:\boost_1_42_0\libs\math\build\jamfile.v2 > > (re-build the pre-compiled header?) > > (cd to that directory and enter "bjam -a > > yourlogfile.log") > > do anything to help? > > Paul > > --- > Paul A. Bristow > Prizet Farmhouse > Kendal, UK LA8 8AB > +44 1539 561830, mobile +44 7714330204 > pbristow(a)hetp.u-net.com > > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

1 0