February 2012 - Boost-users - lists.preview.boost.org

[asio::serial_port] I can read and write synchronously, but how do I unblock when I want to end?
by Dario Ramos 17 Feb '12

17 Feb '12

I'm using boost::asio::serial_port to read and write to a serial port device. I do the reading inside a boost::thread to take advantage of RS-232 being full-duplex. My read calls are like this one: BYTE b; read( m_SerialPort, boost::asio::buffer(&b,1) ); Everything works OK except for shutdown. When I want to end the thread, it's almost always blocked in a read call. How do I unblock it? I tried: - Calling close on the port: This generates an exception, which I can catch, but I was told I can't distinguish shutdown from error if I do this. - Stopping the io_service I passed to the serial_port's constructor. This had no effect, the thread remained blocked on the read call. -- *Darío Eduardo Ramos* Meditech S.A. www.meditech.com.ar (+54) 01147603300, Interno 31 Av. Julio A. Roca 3456 Florida Oeste, Bs.As. Argentina

4 6

Re: [Boost-users] undefined reference to '__sync_add_and_fetch_4'when cross-compiling boost::asio fors mips
by Jayne 17 Feb '12

17 Feb '12

Hello Andreas, Thank you for the reply. I have made some progress since my initial post, I have found that part of the problem is that I am using gcc 4.2 and the various #defines for atomics assume that 4.2 will have the appropriate support. The compiler expects that `__sync_add_and_fetch_4' will be provided. I've found there is some assembler provided with the compiler which gives a 'atomic_exchange_and_add' macro which I've had working correctly in a demo programme, but I haven't yet got it integrated with boost, though that would be a nice long-term solution. Back to the problem though. I've tried a clean build with BOOST_ASIO_DISABLE_FENCED_BLOCK but I'm still getting the same problem. I've attached the build output below. Here are the steps I took to make the clean build: 1. unzip boost_1_48_0.zip 2. mkdir boost-binary 3. set and export BOOST_BUILD_ROOT=/home/jayne/boost-stb/boost_1_48_0 export BOOST_BUILD_ROOT BOOST_BIN_ROOT=$BOOST_BUILD_ROOT/boost-binary export BOOST_BIN_ROOT 4. ./bootstrap.sh 5. Edit the resulting project-config.jam file (which has been generated for the host x86 system) using gcc : mipsel : mipsel-linux-g++ ; and option.set prefix : /opt/brcm/stblinux-2.6.31 ; option.set exec-prefix : /opt/brcm/stblinux-2.6.31 ; option.set libdir : /opt/brcm/stblinux-2.6.31/lib ; option.set includedir : /opt/brcm/stblinux-2.6.31/include/linux ; 6. Edit tools/build/v2/tools/gcc.jam to remove ‘-pendantic’ option (otherwise the string library assembler will not compile) 7. Run ./b2 cxxflags=-DBOOST_ASIO_DISABLE_FENCED_BLOCK --without-python --without-mpi 8. Run ./b2 threading=multi variant=release link=shared toolset=gcc --build-dir=$BOOST_BIN_ROOT --prefix=/tmp/boost --without-python --without-mpi install While compiling in step 7, a typical compiler line is: "mipsel-linux-g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ASIO_DISABLE_FENCED_BLOCK -Wextra -Wno-long-long -pedantic -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DNDEBUG -I"." -c -o "bin.v2/libs/chrono/build/gcc-mipsel/release/threading-multi/process_cpu_clocks.o" "libs/chrono/src/process_cpu_clocks.cpp" This is the output from build: /opt/bcmtools/bin/mipsel-linux-g++ -O2 -I/tmp/boost/include echo_server.o network_utilities.o sha1.o base64.o md5.o uri.o hybi_header.o data.o atomic.o -o echo_server -L/tmp/boost/lib -lboost_regex -lboost_date_time -lboost_program_options -lboost_system -lboost_thread echo_server.o: In function `boost::asio::detail::wait_handler::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail12wait_handlerINS_3_bi6bind_tIvNS_4_mfi3mf0IvN11websocketpp4role6serverINS7_8endpointIS9_NS7_6socket5plainENS7_3log6loggerEEEEEEENS3_5list1INS3_5valueIPSG_EEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x94): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::wait_handler::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail12wait_handlerINS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINS7_8endpointINS7_4role6serverENS7_6socket5plainENS7_3log6loggerEEENSB_ISG_E10connectionENSD_ISG_E10connectionEEERKNS_6system10error_codeEEENS3_5list2INS3_5valueINS_10shared_ptrISL_EEEEPFNS_3argILi1EEEvEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESP_j+0xd4): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_accept_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail25reactive_socket_accept_opINS0_12basic_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS5_EEEES5_NS_3_bi6bind_tIvNS_4_mfi3mf2IvN11websocketpp4role6serverINSD_8endpointISF_NSD_6socket5plainENSD_3log6loggerEEEEENS_10shared_ptrINSD_10connectionISL_NSM_10connectionENSI_ISL_E10connectionEEEEERKNS_6system10error_codeEEENS9_5list3INS9_5valueIPSM_EENS10_IST_EEPFNS_3argILi1EEEvEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESX_j+0xdc): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_service_base::start_op(boost::asio::detail::reactive_socket_service_base::base_implementation_type&, int, boost::asio::detail::reactor_op*, bool, bool)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x1b0): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x2b4): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x2ec): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x3cc): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x548): undefined reference to `__sync_fetch_and_add_4' echo_server.o:echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail28reactive_socket_service_base8start_opERNS2_24base_implementation_typeEiPNS1_10reactor_opEbb+0x65c): more undefined references to `__sync_fetch_and_add_4' follow echo_server.o: In function `boost::asio::detail::reactive_socket_send_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_send_opINS1_17consuming_buffersINS0_12const_bufferEN11websocketpp19shared_const_bufferEEENS1_8write_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceISB_EEEES6_NS1_14transfer_all_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvNS5_4role6serverINS5_8endpointISL_NS5_6socket5plainENS5_3log6loggerEEEE10connectionINS5_10connectionISR_NSS_10connectionENSO_ISR_E10connectionEEEEERKNS_6system10error_codeEEENSG_5list2INSG_5valueINS_10shared_ptrISY_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES13_j+0x1a8): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_send_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_send_opINS1_17consuming_buffersINS0_12const_bufferESt6vectorIS4_SaIS4_EEEENS1_8write_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceISC_EEEES7_NS1_14transfer_all_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINSL_8endpointINSL_4role6serverENSL_6socket5plainENSL_3log6loggerEEENSP_ISU_E10connectionENSR_ISU_E10connectionEEERKNS_6system10error_codeEEENSH_5list2INSH_5valueINS_10shared_ptrISZ_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES13_j+0x208): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::epoll_reactor::descriptor_state::perform_io(unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state10perform_ioEj+0x244): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state10perform_ioEj+0x324): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `boost::asio::detail::epoll_reactor::descriptor_state::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x21c): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail13epoll_reactor16descriptor_state11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationERKNS_6system10error_codeEj+0x340): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `boost::asio::detail::reactive_socket_recv_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_recv_opINS0_17mutable_buffers_1ENS1_26read_until_delim_string_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS7_EEEESaIcENS_3_bi6bind_tIvNS_4_mfi3mf2IvN11websocketpp4role6serverINSG_8endpointISI_NSG_6socket5plainENSG_3log6loggerEEEE10connectionINSG_10connectionISO_NSP_10connectionENSL_ISO_E10connectionEEEEERKNS_6system10error_codeEjEENSC_5list3INSC_5valueINS_10shared_ptrISV_EEEEPFNS_3argILi1EEEvEPFNS17_ILi2EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationES10_j+0x13c): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `boost::asio::detail::reactive_socket_recv_op::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned int)': echo_server.cpp:(.gnu.linkonce.t._ZN5boost4asio6detail23reactive_socket_recv_opINS0_17mutable_buffers_1ENS1_17read_streambuf_opINS0_19basic_stream_socketINS0_2ip3tcpENS0_21stream_socket_serviceIS7_EEEESaIcENS1_19transfer_at_least_tENS_3_bi6bind_tIvNS_4_mfi3mf1IvN11websocketpp10connectionINSH_8endpointINSH_4role6serverENSH_6socket5plainENSH_3log6loggerEEENSL_ISQ_E10connectionENSN_ISQ_E10connectionEEERKNS_6system10error_codeEEENSD_5list2INSD_5valueINS_10shared_ptrISV_EEEEPFNS_3argILi1EEEvEEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESZ_j+0x104): undefined reference to `__sync_lock_test_and_set_4' echo_server.o: In function `websocketpp::message::intrusive_ptr_release(websocketpp::message::data const*)': echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x34): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x114): undefined reference to `__sync_fetch_and_add_4' echo_server.cpp:(.gnu.linkonce.t._ZN11websocketpp7message21intrusive_ptr_releaseEPKNS0_4dataE+0x244): undefined reference to `__sync_fetch_and_add_4' echo_server.o: In function `std::deque::_M_push_back_aux(boost::intrusive_ptr const">On Fri 17/02/12 07:01 , "Andreas Wehrmann" a.wehrmann(a)centersystems.com sent: On 02/16/2012 10:06 AM, Jayne wrote: > > Hello, > > I'm trying to build Boost 1.48.0 for use with the WebSockets++ library > on a MIPS based embedded Linux board. > > My build machine reports itself as: Linux version 2.6.40.4-5.fc15.x86_64 > (mockbuild(a)x86-10.phx2.fedoraproject.org) (gcc version 4.6.0 20110603 > (Red Hat 4.6.0-10) (GCC) ) #1 SMP Tue Aug 30 14:38:32 UTC 2011 > > My cross-compiler version is: mipsel-linux-g++ (GCC) 4.2.0 20070124 > (prerelease) - BRCM 11ts-20090508. I don't have any control over this as > its provided by the chip manufacturer. > > I can build Boost without any reported errors and can link to and use > most of the libraries without any problems. However, when WebSockets > tries to link to the Boost::asio library I get link errors like this: > > (.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x30): > undefined reference to `__sync_add_and_fetch_4' > > (.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x80): > undefined reference to `__sync_add_and_fetch_4' > > (.gnu.linkonce.t._ZN11websocketpp9processor4hybiINS_10connectionINS_8endpointINS_4role6serverENS_6socket5plainENS_3log6loggerEEENS5_ISA_E10connectionENS7_ISA_E10connectionEEEE19prepare_close_frameEN5boost13intrusive_ptrINS_7message4dataEEENS_5close6status5valueERKSs+0xc8): > more undefined references to `__sync_add_and_fetch_4' follow > > I've done enough research to find this has been a problem in the past > with ARM chips and is to do with atomic transactions not being > implemented by gcc for the target machine. I've tried the suggested > fixes for ARM which were to build with either BOOST_SP_DISABLE_THREADS > or BOOST_SP_USE_PTHREADS but that didn't help with my MIPS environment. > > Can anyone make any suggestions as to what I could try next? > > thanks, > > Jayne. > Try this #define: BOOST_ASIO_DISABLE_FENCED_BLOCK -- Dipl.-Ing. (FH) Andreas Wehrmann Software Development -------------------------------------------------------------- Center Communication Systems GmbH Sitz in Wien FN 796 88p, Firmenbuchgericht Wien http://www.centersystems.com [1]">www.centersystems.com Tel.: +43 (0) 190 199 - 3616 Mobile: +43 (0) 664 884 75916 Fax: +43 (0) 190 199 - 2110 E-Mail: a.wehrmann(a)centersystems.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users [2]">http://lists.boost.org/mailman/listinfo.cgi/boost-users Links: ------ [1] http://www.centersystems.com [2] http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 1

Remove certificate from asio::ssl::context
by Lloyd 17 Feb '12

17 Feb '12

Hi, I am using a "single context object" loaded with necessary certificates, for a SSL based communication in the server side. The certificates are loaded with the call "use_certificate_file()". Is there any way that I can remove a certificate from the context. If this is not possible, is there any possibility of clearing the context, and reloading only the new necessary certificates? Thanks, Lloyd

1 0

[heap] Boost heap and default constructors for comparators
by Evan Driscoll 17 Feb '12

17 Feb '12

The Boost heap library (at least binomial and fibonacci heaps) requires a default constructor of its comparator in order to call 'pop()' on a heap. I ran into this because I was trying to use a std::binary_negate<> wrapper around another comparator: this has no default constructor. So it's pretty easy to work around; I just have to provide a custom version of binary_negate. However, is this intentional? Should it be fixed? The problem is a little strange; it only surfaces if you call the 'pop()' function of the heap. If you look at the error location, binomial_heap.hpp:831, it is // private constructor, just used in pop() explicit binomial_heap(node_list_type & child_list, size_type size): super_t(value_compare()) To wit, with 1.49 beta 1: #include <boost/heap/binomial_heap.hpp> using namespace boost::heap; struct cmp { # ifdef MAKE_DEFAULT_CONSTRUCTOR cmp() {} # endif cmp(int a) {} bool operator() (int a, int b) const { return a < b; } }; int main() { cmp c(1); binomial_heap<int, compare<cmp> > h(c); h.push(1); # ifdef CALL_POP h.pop(); # endif } Compiling with CALL_POP undefined works. Adding -DCALL_POP then causes a compiler error (the following from GCC 4.3.2, but also witnessed with MSVC10): boost_1_49_0_beta1/boost/heap/binomial_heap.hpp: ... heap.cpp:21: instantiated from here boost_1_49_0_beta1/boost/heap/binomial_heap.hpp:831: error: no matching function for call to ‘cmp::cmp()’ heap.cpp:9: note: candidates are: cmp::cmp(int) heap.cpp:5: note: cmp::cmp(const cmp&) Adding -DMAKE_DEFAULT_CONSTRUCTOR works again.

2 1

Can boost be compiled on WinCE?
by Luke Walker 17 Feb '12

17 Feb '12

Hi,I'm required to compile existing code on WinCE that uses boost::asio, boost::thread, boost::system and boost::spirit (wide strings). I attempted this and made allot of progress but eventually ran into so many dead-ends (locale, wide strings, etc, etc) that I had to quit and make this post. My questions are: Can these 4 libraries be compiled and used on WinCE? I'm not seeking a theoretical answer but rather "Has this been accomplished?". After scouring google, etc for two days straight have not found any reference to any person that actually compiled and got boost working on WinCE. I did however find plenty of evidence that it's being "attempted". Most of the posts remain unanswered. I would appreciate some help here. Thanks and take care.

3 3

undefined reference to '__sync_add_and_fetch_4' when cross-compiling boost::asio fors mips
by Jayne 17 Feb '12

17 Feb '12

Hello, I'm trying to build Boost 1.48.0 for use with the WebSockets++ library on a MIPS based embedded Linux board. My build machine reports itself as: Linux version 2.6.40.4-5.fc15.x86_64 (mockbuild(a)x86-10.phx2.fedoraproject.org) (gcc version 4.6.0 20110603 (Red Hat 4.6.0-10) (GCC) ) #1 SMP Tue Aug 30 14:38:32 UTC 2011 My cross-compiler version is: mipsel-linux-g++ (GCC) 4.2.0 20070124 (prerelease) - BRCM 11ts-20090508. I don't have any control over this as its provided by the chip manufacturer. I can build Boost without any reported errors and can link to and use most of the libraries without any problems. However, when WebSockets tries to link to the Boost::asio library I get link errors like this: (.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x30): undefined reference to `__sync_add_and_fetch_4' (.gnu.linkonce.t._ZNSt5dequeIN5boost13intrusive_ptrIN11websocketpp7message4dataEEESaIS5_EE16_M_push_back_auxERKS5_+0x80): undefined reference to `__sync_add_and_fetch_4' (.gnu.linkonce.t._ZN11websocketpp9processor4hybiINS_10connectionINS_8endpointINS_4role6serverENS_6socket5plainENS_3log6loggerEEENS5_ISA_E10connectionENS7_ISA_E10connectionEEEE19prepare_close_frameEN5boost13intrusive_ptrINS_7message4dataEEENS_5close6status5valueERKSs+0xc8): more undefined references to `__sync_add_and_fetch_4' follow I've done enough research to find this has been a problem in the past with ARM chips and is to do with atomic transactions not being implemented by gcc for the target machine. I've tried the suggested fixes for ARM which were to build with either BOOST_SP_DISABLE_THREADS or BOOST_SP_USE_PTHREADS but that didn't help with my MIPS environment. Can anyone make any suggestions as to what I could try next? thanks, Jayne.

2 1

[serialization] compile-time detection of whether serialization is implemented for a class
by Nelson, Erik - 2 17 Feb '12

17 Feb '12

I'm using the Serialization library and am trying to find a way to detect at compile-time whether or not serialization is implemented for a given type. For example, if I have #include "boost/archive/binary_oarchive.hpp" #include <strstream> struct A{}; void function() { const A a; std::strstream s; boost::archive::binary_oarchive oa(s); oa << a; } I get an error (as expected) along the lines of C:\work\boost\boost/serialization/access.hpp(118): error C2039: 'serialize' : is not a member of 'A' What I'd like is a compile-time way of detecting that 'A' is not serializable, maybe Boost Type Traits-style, something like is_serializable<A>::value or is_serializable<binary_oarchive, A>::value that can detect whether or not the object has serialization available. If it could work for testing pointer serialization as well (is_serializable<A*>::value or is_ptr_serializable<A>::value) that would be doubly super. Thanks Erik ---------------------------------------------------------------------- This message w/attachments (message) is intended solely for the use of the intended recipient(s) and may contain information that is privileged, confidential or proprietary. If you are not an intended recipient, please notify the sender, and then please delete and destroy all copies and attachments, and be advised that any review or dissemination of, or the taking of any action in reliance on, the information contained in or attached to this message is prohibited. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Sender. Subject to applicable law, Sender may intercept, monitor, review and retain e-communications (EC) traveling through its networks/systems and may produce any such EC to regulators, law enforcement, in litigation and as required by law. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or free of errors or viruses. References to "Sender" are references to any subsidiary of Bank of America Corporation. Securities and Insurance Products: * Are Not FDIC Insured * Are Not Bank Guaranteed * May Lose Value * Are Not a Bank Deposit * Are Not a Condition to Any Banking Service or Activity * Are Not Insured by Any Federal Government Agency. Attachments that are part of this EC may have additional important disclosures and disclaimers, which you should read. This message is subject to terms available at the following link: http://www.bankofamerica.com/emaildisclaimer. By messaging with Sender you consent to the foregoing.

3 9

Boost Python and Crypto++
by Boost Users List 16 Feb '12

16 Feb '12

Hi, I'm trying to use Crypto++ with boost::python. My code seems to build OK, but when I try to import it into Python, I receive this error: ImportError: nf_decrypt.so: undefined symbol: _ZN8CryptoPP21SimpleKeyingInterface6SetKeyEPKhmRKNS_14NameValuePairsE Here is the cpp source code file: #include <cryptopp/aes.h> #include <cryptopp/hex.h> #include <cryptopp/modes.h> std::string nf_decrypt( const std::string& estring ) { std::string hex_pk = "00000000000000000000000000000000"; std::string hex_iv = "00000000000000000000000000000000"; std::string pk; std::string iv; std::string cipher_text; std::string plain_text; CryptoPP::StringSource ( hex_pk.c_str(), true, new CryptoPP::HexDecoder( new CryptoPP::StringSink(pk) ) ); CryptoPP::StringSource ( hex_iv.c_str(), true, new CryptoPP::HexDecoder( new CryptoPP::StringSink(iv) ) ); CryptoPP::StringSource ( estring.c_str(), true, new CryptoPP::StringSink(cipher_text) ); CryptoPP::AES::Decryption aesDecryption( (byte*)pk.c_str(), CryptoPP::AES::DEFAULT_KEYLENGTH ); CryptoPP::CBC_Mode_ExternalCipher::Decryption cbcDecryption( aesDecryption, (byte*)iv.c_str() ); CryptoPP::StringSource( cipher_text, true, new CryptoPP::StreamTransformationFilter( cbcDecryption, new CryptoPP::StringSink(plain_text))); return plain_text; } // python wrapper #include <boost/python.hpp> BOOST_PYTHON_MODULE(nf_decrypt) { boost::python::def("nf_decrypt", nf_decrypt, boost::python::args("string_to_decrypt"), "nf_decrypt docstring"); } Has anyone built boost python extensions from Crypto++ code? I may try doing the same thing with Botan if Crypto++ in general is problematic. I can send my Jamroot file if that would be helpful. Thanks for any advice.

2 1

[boost.iostreams] using zlib with wide streams
by Sean Farrow 16 Feb '12

16 Feb '12

Hi: Is is possible ot use zlib/bzip2 with wide streams. Any help appreciated. Cheers Sean.

1 0

Re: [Boost-users] Developing a new boost archive
by Roberto Fichera 16 Feb '12

16 Feb '12

Actually I cannot really answer because I haven't had yet a deeper look at the suggest "export" method details. Neverthelss, what I need is an explicit string because certain format might require such information used to instantiate objects of the given class while deserializing in other languages (java or python for example). But also pure text formats optionally provide this information with the purpose of helping the user to understand/verify the content of the result of the serialization. My library, which is written in pure C code for compatibility reasons, does solves easily the problem by stringify the given type via pretty straight macro inside the serialization function itself. Something like opening a type, serialize all the fields and close the type. The use of the macro obviously doesn't work at all when using it under any template declaration because the preprocessor is called earlier in compilation process. I also tried the parsing of the __PRETTY__FUNCTION__ which works perfectly under template function, but this approach is even more un-portable then the demangler, so not really praticable. Sent from my ASUS Eee Pad Larry Evans <cppljevans(a)suddenlink.net> wrote: >On 02/15/12 12:38, Robert Ramey wrote: >> Roberto Fichera wrote: >>> On 02/15/2012 06:01 PM, Robert Ramey wrote: >> >>>> c) Even worse, the aproach above would make even text archives >>>> non-portable between platforms. Of course this is a non-starter. >>>> So you might want to re-think your approach above. >>> >>> I agree totally with you! Actually my constraint is to use gnu >>> toolchain, >>> MSVC and pathscale compilers and eventually LLVM, but this one is not >>> a priority at moment. But, any way still the problem of the demangling >>> portability. >>> >>> By the way, how did you solve the problem ... if you solved it, >>> indeed ;-) ? >> >> It is already solved portably via the "export" functionality. Look >> it up in the documentation. >> >> Robert Ramey >Hi Robert, > >Looking at: > > http://www.boost.org/doc/libs/1_48_0/libs/serialization/doc/serialization.h… > >and reading: > > The system "registers" each class in an archive the first time an > object of that class it is serialized and assigns a sequential > number to it. Next time an object of that class is serialized in > that same archive, this number is written in the archive. So every > class is identified uniquely within the archive. When the archive > is read back in, each new sequence number is re-associated with the > class being read. Note that this implies that "registration" has to > occur during both save and load so that the class-integer table > built on load is identical to the class-integer table built on > save. In fact, the key to whole serialization system is that things > are always saved and loaded in the same sequence. This includes > "registration". > >And paraphrasing part as: > > So every class is identified by this uniquely assigned sequential > number within the archive. > >Then I'd infer that this "uniquely assigned sequential number" play >a role similar to the role of the result of: > > abi::__cxa_demangle( typeid( T ).name(), 0, 0, NULL ); > >in Roberto's post: > > http://article.gmane.org/gmane.comp.lib.boost.user/72805 > >As you mention, Roberto's method is not portable between platforms >(where, of course, a different compiler or even different version >of the same compiler would be a different platform). > >OTOH, as you also mention in the above quote, boost serialization >requires: > > things are always saved and loaded in the same sequence. > >Roberto, would that be a problem for you? > >-regards, >Larry > > > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[Program_options] How to parse a command-line incrementally
by Olaf Meeuwissen 16 Feb '12

16 Feb '12

Hi all, I'm looking to implement an "incremental" command-line parser using Boost.Program_options. The parser should be incremental in the sense that parsing should stop at the first unknown option or positional argument. At this point, my program would pick the next options description and continue parsing with that. This would proceed until the command-line has been parsed completely or the program is no longer interested in the remainder. The idea is to use this for a program that interfaces to a collection of commands that each support a set of actions. The program, commands and actions all have their own list of options, so you get command-lines like so prog [prog-opts] [cmd [cmd-opts] [act [act-opts]]] Eventually, I might want to throw in positional arguments for some or each of these as well. Any suggestions on how to achieve this? My main concerns are with the way Boost.Program_options wants to parse the whole command-line (when using allow_unregistered()) every time and with how to keep track of what still needs to be processed. Thanks in advance, -- Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- AVASYS CORPORATION FSF Associate Member #1962 Help support software freedom http://www.fsf.org/jf?referrer=1962

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Boost Phoenix Arguments Passing & Storage (-- Proper Type?) & Application to RValues -- Possible?
by Matt 15 Feb '12

15 Feb '12

Hi there! I've got a question (two, in fact) regarding Arguments in Boost Phoenix. Assuming using boost::phoenix::arg_names::arg1; using boost::phoenix::val; using boost::phoenix::ref; using boost::phoenix::cref; Why does this compile (and works): int x = 1; int y = 2; std::cout << (arg1 % 2 == 1)(x) << '\n'; std::cout << (arg1 % 2 == 1)(y) << '\n'; while these fail to compile (with an extremely long diagnostic involving "boost::error_cant_deduce_type"): std::cout << (arg1 % 2 == 1)(1) << '\n'; std::cout << (arg1 % 2 == 1)(2) << '\n'; std::cout << (arg1 % 2 == 1)(val(1)) << '\n'; std::cout << (arg1 % 2 == 1)(val(2)) << '\n'; std::cout << (arg1 % 2 == 1)(cref(1)) << '\n'; std::cout << (arg1 % 2 == 1)(cref(2)) << '\n'; I run into this was while attempting to store an Arg. into a variable, i.e.,: auto f = (arg1 % 2 == 1); this works: std::cout << f(x) << '\n'; std::cout << f(y) << '\n'; while this fails: std::cout << f(1) << '\n'; std::cout << f(2) << '\n'; I'm guessing this must be for the same reason the above attempts fail. Another question is, what's the "proper" type of "f" assuming non-C++11 compiler? I'd like to avoid wrappers like boost::function (assuming that's even possible). Later on, I'd like to return such an "f" from a function, hence the question (in C++11 I can get away with decltype for short and easy ones, i.e., prototypes like this "auto newActor() -> decltype((arg1 % 2 == 1))" work, but this becomes inconvenient for longer bodies). A concoction like this compiles but doesn't produce an output: auto f = (val(arg1) % 2 == 1); std::cout << f(val(0)) << '\n'; // and I'm guessing this is very wrong anyway due to unusual behavior. Best, Matt

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Developing a new boost archive
by Roberto Fichera 15 Feb '12

15 Feb '12

Hi All in the list, I'm basically new to boost so I hope to find support here to integrate my own serialization library within the boost archive logic. I would say as premise that I started to have a look in all the boost archive implementation so binary, xml and text trying to understand the logic but that increased my confusion about how to approach the solution of my problem. Confusion that is increased by the lack of my boost knowledge and it's related template programming, of course. By the way I found really instructive the simple_log_archive example that cleanly shows how to "walk" the full tree of the data representation in terms of serialization chain. Furthermore, I would say that my serialization framework does already handle all the representation formats like binary, xml, text, python and many others, so from the boost archive point of view I need just to know very few things: - how to walk the tree representing the serialization chain - how to detect that a new type is being serialized - how to get the type name as string - how to define primitive types - how to manage vectors/arrays - be sure that everything is passed as nvp About the two first, they seems related because the code below seems responsible to walk the tree and call all the serialize functions template< class Archive > struct save_only { template< class T > static void invoke( Archive & ar, const T & t ) { // make sure call is routed through the highest interface that might // be specialized by the user. boost::serialization::serialize_adl( ar, const_cast< T & >( t ), boost::serialization::version< T >::value ); } }; So I've put my two functions that are used to defines types: myserialize_beginType( myserialize &s, char *fieldName, char *type ) myserialize_endType( myserialize &s ) Such as the serialization walk chain looks like: template< class Archive > struct save_only { template< class T > static void invoke( Archive & ar, const T & t ) { // make sure call is routed through the highest interface that might // be specialized by the user. -->> myserialize_beginType( ar.serializer, ar.fieldName, ???type??? ); boost::serialization::serialize_adl( ar, const_cast< T & >( t ), boost::serialization::version< T >::value ); -->> myserialize_endType( ar.serializer ); } }; But actually I don't know how to determine the type name as string to pass to my beginType function. About the place to define primitives, I'm not really sure if it's the right place where I have to put my serialization primitives that maps all my basics types. The prototype of such overloaded function is like myserialize_serialize( "basetype" &t, char * fieldName, myserialize &s ) Actually I've defined something like: #define BOOSTSERIALIZEARCHIVE_PRIMITIVE( __T ) \ simple_log_archive & operator<<( const boost::serialization::nvp< __T > & t )\ {\ myserialize_serialize( t.value(), (char*)t.name(), this->serializer );\ return *this;\ } BOOSTSERIALIZEARCHIVE_PRIMITIVE( char ) BOOSTSERIALIZEARCHIVE_PRIMITIVE( unsigned char ) which seems to work. About managing vectors and array, actually I tried to define something like: template< class Archive > struct use_array_optimization { template < class T > static void invoke( Archive & ar, const T & t ) { myserialize_serialize( (T*)t.address(), ar.fieldName , t.count() * sizeof( T ), ar.serializer ); } }; template< class T > void save( const T &t ) { typedef BOOST_DEDUCED_TYPENAME boost::mpl::eval_if<boost::is_enum< T >, boost::mpl::identity<save_enum_type<simple_log_archive> >, // else -->> BOOST_DEDUCED_TYPENAME boost::mpl::eval_if<boost::is_array< T >, -->> boost::mpl::identity<use_array_optimization<simple_log_archive> >, //else BOOST_DEDUCED_TYPENAME boost::mpl::eval_if< // if it's primitive boost::mpl::equal_to< boost::serialization::implementation_level< T >, boost::mpl::int_<boost::serialization::primitive_type> >, boost::mpl::identity<save_primitive<simple_log_archive> >, // else boost::mpl::identity<save_only<simple_log_archive> > > > >::type typex; typex::invoke( *this, t ); } but this seems not working at all. Finally the last items, be sure that everything is passed as nvp in order to catch each given field name, I simply don't know how to do this check/constraint. Hopefully to get some support. Thanks in advance, Roberto Fichera.

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Dependency Issue
by Guruswamy B M 15 Feb '12

15 Feb '12

Hi, I am using boost python for one of my application. It works fine in a machine where visual studio installed. If visual studio removed then app will through a error ""ImportError: DLL load failed: This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem.". I have searched through internet, but I am not able find a proper solution for this. However i have installed 2008 visual studio redistribution package. Also I resolved dependency problem which is shown by dependency walker. Any help regarding this issue greatly appreciated. Thanks, Guru

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[range] count vs count_if
by Bill Buklis 15 Feb '12

15 Feb '12

The documentation for boost range states that count_if can be expressed as count using a filtered adaptor and then goes on to say that no algorithm needs the _if suffix. I'm having trouble seeing how that is the case. Here is the relevant section from the latest (1.49 beta) documentation <http://www.boost.org/doc/libs/1_49_0_beta1/libs/range/doc/html/range/refere…>. Range Adaptor alternative to count_if algorithm <http://www.boost.org/doc/libs/1_49_0_beta1/libs/range/doc/html/range/refere…> boost::count_if( rng, pred ); can be expressed as boost::count( rng | boost::adaptors::filtered(pred), out ); What this means is that /*no*/ algorithm with the |_if| suffix is needed. First of all, what is "out"? I think this is supposed to be "value" as count requires the value to compare against for the count. But, since it does require the value, this makes the function fundamentally different than count_if which will only count the values that match the predicate. As far as I can tell, this means that "count" will filter values both by the predicate and by the value. What am I missing? How can count_if be properly expressed as count. To me it seems like it can't. -- Bill

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MSVC static linking with Boost
by Andy Falanga (afalanga) 14 Feb '12

14 Feb '12

Hi, The team I work with is working on producing a Boost.Python library. Most of the Boost stuff we're using are header only, however, there is a couple of compiled library usages as well (e.g. regex). How can we make certain that the library we're building is statically linked with the stuff we're using from Boost? This way, we don't have to deploy any other DLLs but our own. I've gathered, from Google and another post here, that most of this magic happens at compile time with auto-linking. However, this isn't going all the way. I continually see Intellisense errors in my Visual Studio output window telling me that mixing static and dynamic Boost libraries is a bad idea (or something similar). So, for Visual Studio 2010, how do I ensure that the libraries are statically linked into our own product? Thanks, Andy

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BoostCon/C++Now! Talk: How I Code and Why
by Gottlob Frege 14 Feb '12

14 Feb '12

I talked about this last year, and this year I've submitted the proposal, so If you volunteered last year (and are still interested) and/or are interested in helping with a particular/peculiar talk at BoostCon/C++Now this year, then read on, and contact me offline: I'm planning on giving a talk, entitled "How I Code and Why". It is not meant to be presumptuous and tell you how *you* should code, but instead just explains how I code - day-to-day - and how I came to these patterns/conclusions. But who cares just about how *I* code, people want to hear how other members of the Boost community - people they've come to know and respect via the boost lists - code. So I'm hoping to have a few co-conspirators on stage with me, and have each explain a fundamental guiding principle that they follow in their every day code, how they came to adopt this principle and why they find it valuable. For example, I will tell the simple story ('epiphany') of why my favourite comment word is 'otherwise', and how this relates to advice you may have heard or read before. I like the flavour of [ simple, real world, specific ] ---> [ general principle ] The goal is to bring a more real world down to earth picture to the sometimes lofty fundamentals found in books and lectures. Instead of a book explaining how a guiding principle makes sense *in theory*, it would be great (I think) to hear how respected members of the community apply these principles in real life. So, if you want to participate, email me, and we will see what we can figure out. (And/or I might just have to track you down based on promises made last year!) Not sure how many people we need. I'm thinking 5-15 mins per 'principle', and I think you only need to present one (I think the weight of picking *just one* principle makes it all the more interesting). Anyhow, we can work out the details as we go along. Tony PS. this is not (yet?!) an accepted talk, but I have a bit of chicken/egg thing here: ie it would help to have a few people on board to show that the talk is viable, and thus be accepted.

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A plea for simpler tools
by Robert Ramey 14 Feb '12

14 Feb '12

Let me start by saying I love Boost and C++ as much or more than anyone here!!! But I'm really frustrated with the boost tools and believe they are a serious impediment to the progress of boost. Here is what I want to be able to do: a) create a directory structure outside of the boost tree which looks like: mylib build include src doc html docbook(maybe) boostbook(maybe) quickbook(maybe) test results ... b) a set of simple tools which 1) can build the library in the src directory 2) can translate quick/boost/doc book to html and place it in that directory 3) run each test in the test directory and add a record to the test/results/... log file which I will either just lookat or post process locally to my personal taste. c) what I don't need 1) tracking dependencies - I want to do this for on library I might be experimenting with. I can do this by hand. 2) I don't need to have my boost tree updated - in fact I want to know that I haven't changed it by just running a simple tool d) current tools: 1) presume that a library is part of the boost directory structure. So the documents show up somewhere in the boost tree. Note when I build the documents on my local boost release image I get pointers to the boost sandbox or on sourceforge.net or whatever. So for boostbook->html would like to be able to say boostbook2html -in <boostbookdir> -out <htmldirectory> or something simple like this. 2) the only way I've found to use the current tools is to create directories in my local boost release tree with my "experimental" library and run bjam. There are two problems with this i) I have to make a jamfile which might be more complicated that first meets the eye ii) I mucks up my boost release tree. iii) it I get something wrong, it fails deep within some bjam script which is extremely difficult to figure out. iv) For an example to iii) above, I had tweaked userconfig.v2 to include the name of my xsltproc program which was found through the path. Later I elimnated the directory of the xsltproc from my path. Later I found I couldn't build my library or run any tests. Turned out that bjam stopped when it failed to find the xsltproc program - even though it wasn't being used. I'm not critisizing bjam. I think it's impossible to make a program as ambituous as this totally perfect. But I question the need for such an elaborate tool for doing what seems to me should be something simple. Of course, I can do this myself - and likely will end up doing so. But: a) I've got other stuff to do b) I can't believe I'm the only one who needs this c) I think that boost tools are "too automatic" for my purposes. I understand the motivation for building all of boost. But for what I want to do it adds a huge layer of "conceptual overhead" that I have to wade through. Before I invest effort in this perhaps there's a way of using existing tools that I'm not aware that get's me closer to what I want and need. Comments welcome. Robert Ramey

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graph planar_face_traversal
by Andreas Fabri 14 Feb '12

14 Feb '12

Hello, I am wondering about the output of the example on the page http://www.boost.org/doc/libs/1_48_0/libs/graph/doc/planar_face_traversal.h… I would expect that the vertices on the border of the outer or unbounded face got reported in reverse order. The vertices of inner faces are reported in clockwise order which makes that for each edge shared by inner faces, we traverse it once from source to target, and once from target to source. This does not hold for edges on the outer face. Is this intentional, or just a documentation bug? Best regards, Andreas -- Andreas Fabri, PhD Chief Officer, GeometryFactory Editor, The CGAL Project phone: +33.492.954.912 skype: andreas.fabri

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Boost Date/Time
by asif saeed 13 Feb '12

13 Feb '12

Hi, I get a run-time error when I run the following code; std::string LocaleFormattedDateTime (::boost::posix_time::ptime pt) { std::string s; std::ostringstream ss; //::boost::posix_time::time_facet * tf = new ::boost::posix_time::time_facet; ::boost::posix_time::time_facet tf; //std::locale custom_locale (std::locale(""), tf); std::locale custom_locale (std::locale(""), &tf); // custom_locale takes ownership of the tf facet ss.imbue (custom_locale); //(*tf).format("%Y%m%d-%H%M%S-%f"); // date time tf.format("%Y%m%d-%H%M%S-%f"); // date time ss << pt; // don't explicitly delete tf - what's wrong with a stack variable? why this runtime error? What is the point of new() above and //what if I don't delete allocated memory here. return ss.str(); } void CurrentDateTimeWithMicroseconds(char s[], int sz = 100) { using namespace boost::posix_time; using namespace std; using boost::date_time::date_facet; ptime t = microsec_clock::local_time(); ostringstream ss; //time_facet *df = new time_facet(); time_facet df; //std::locale loc (std::locale(""), df); std::locale loc (std::locale(""), &df); ss << LocaleFormattedDateTime(t) ; memset(s,0,sz); strcpy(s,ss.str().c_str()); } Can you tell me the problem? I modified this code after copying this from some online source. Thanks in advance, Asif

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[date_time] greg_day_of_week as numeric type
by Claude 13 Feb '12

13 Feb '12

It is possible transform or use the greg_day_of_week (day_of_week() method) as a numeric type? Also seems to me that there is no day_of_month() method. Why? -- View this message in context: http://boost.2283326.n4.nabble.com/date-time-greg-day-of-week-as-numeric-ty… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] Poor/erratic boost::interprocess named_semaphore performance
by Davidson, Josh 13 Feb '12

13 Feb '12

Ok, so I converted my example to native Windows semaphores, and it consistently completes in less than 250ms (up to 160x faster). Something is definitely going on. -----Original Message----- From: Davidson, Josh Sent: Sunday, February 12, 2012 9:01 PM To: boost-users(a)lists.boost.org Subject: Poor/erratic boost::interprocess named_semaphore performance I'm experiencing performance issues using named semaphores on Windows 7 x64. Currently, I'm on 1.49 beta 1, but the behavior was similar on 1.48 and 1.47. Below, I'm copying two sample programs. They simply synchronize with one another using a pair of semaphores. To run them, start the first program and then the second. They will synchronize with each other 100k times and then the second program will spit out the elapsed time. You can restart the second program to run again without bringing down the first program. On Windows, the elapsed time the first time around is anywhere from 20 - 40 seconds. If you leave the second program running, the following run will be only about 2-3 seconds. A third run it will be back up to 20-40 seconds, and it will keep bouncing back and forth like that. On Linux, the total elapsed time is consistently less than half a second. I'm guessing the Windows implementation isn't as efficient, but I wouldn't expect it to be 100 times slower than Linux. The other perplexing thing is how wildly different the results are on Windows from run to run. =====================Test1.cpp========================================== #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost::posix_time; #include <boost/interprocess/sync/named_semaphore.hpp> using namespace boost::interprocess; #include <iostream> using namespace std; int main() { named_semaphore::remove("sem1"); named_semaphore::remove("sem2"); named_semaphore sem1(create_only_t(), "sem1", 0); named_semaphore sem2(create_only_t(), "sem2", 0); while(true) { sem1.wait(); sem2.post(); } return 0; } =====================Test2.cpp========================================== #include <boost/interprocess/sync/named_semaphore.hpp> using namespace boost::interprocess; #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost::posix_time; #include <iostream> using namespace std; int main() { const size_t iterations = 100000; named_semaphore sem1(open_only_t(), "sem1"); named_semaphore sem2(open_only_t(), "sem2"); ptime start = boost::posix_time::microsec_clock::local_time(); for(size_t i = 0; i < iterations; ++i) { sem1.post(); sem2.wait(); } ptime end = boost::posix_time::microsec_clock::local_time(); time_duration delta = end - start; double seconds = double(delta.total_nanoseconds())/1000000000.0; cout << "Total elapsed time: " << seconds << endl;; cout << "Time per iteration: " << (seconds/double(iterations)) << endl; return 0; }

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iterating though an inifile section using boost.property_tree
by Sean Farrow 13 Feb '12

13 Feb '12

Hi Fokes: Ok, I've got a standard windows-stle ini file. I can check that a section exists, and then get that section, using it->second, where it is declared as: boost::property_tree::ptree::const_assoc_iterator it; I've then assigned the it->second variable to a new property_tree. What I now need to do is iterate though the tree I've just assigned and get all the section keys/values. I'm using the following code to add them all to a map: std::map<string, string> SectionProps; BOOST_FOREACH(boost::property_tree::ptree::value_type &v, SectionTree) { Key =v.first; Value =v.second; SectionProps.insert(std::make_pair(Key, Value)); } It seems that even though thwe values in the ini file will be strings, of the vorm Key1=valu1 as normal, I am still getting another ptree as my second argument of the pair. How do I obtain the value from this? There are never any sub sections. Any help appreciated. Cheers Sean.

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[tuple] Tuple arithmetic
by Bill Buklis 13 Feb '12

13 Feb '12

Is there any facility to perform arithmetic operations on a tuple? For example: struct data { double a, b; }; data d1 = {1.0, 2.0}; data d2 = {2.5, 5.5}; // These two lines are not valid, but simulate what I want. boost::tie(d1.a, d1.b) *= 10.0; // Multiply each element by 10.0 boost::tie(d1.a, d1.b) += boost::tie(d2.a, d2.b); // Add the elements from the second object After calculations, d1 should equal {12.5, 25.5}; Thanks, -- Bill

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[Format] No implicit conversion to string?
by John M. Dlugosz 13 Feb '12

13 Feb '12

It's shown prominently in the docs that a boost::format object can be sent to an ostream. cout << format("%2% %1%") % 36 % 77; But, there is no easy way to use it where a plain string is needed. E.g. throw runtime_error ( format("%2% %1%") % 36 % 77 ); One must use extra parens and a named function, either throw runtime_error ( (format("%2% %1%") % 36 % 77).str() ); or throw runtime_error ( str(format("%2% %1%") % 36 % 77) ); either of which detracts from the expression. Is there any good reason why an implicit conversion operator to the matching string class was omitted? I'd like to find out if there is some reason, before looking into submitting an update. —John

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