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linker error boost with 1.69 and 1.70
by Danny K 20 May '19

20 May '19

So I have been using boost for awhile. I compile boost the same way for all the versions and have been since 1.48. My platforms are CentOS 6 & 7 and Windows 10 vs2017. My code has compiled on all 3 platforms with Boost without a problem. My current version is 1.66 and I wanted to upgrade to 1.69. Under Windows, I build 1.69 with ZLIB & BZIP and my applications have no problems. I use zlib & bzip in the IOstreams library to read & write compressed files. So I built 1.69 under Linux the same way as I always have but I am now getting a linker error that I don't understand and I am stuck. The error starts with: API_utiltyFunctions.cpp:(.text+0x154): undefined reference to `boost::iostreams::detail::zlib_base::before(char const*&, char const*, char*&, char*)' API_utiltyFunctions.cpp:(.text+0x15b): undefined reference to `boost::iostreams::zlib::sync_flush' API_utiltyFunctions.cpp:(.text+0x165): undefined reference to `boost::iostreams::detail::zlib_base::xinflate(int)' API_utiltyFunctions.cpp:(.text+0x177): undefined reference to `boost::iostreams::detail::zlib_base::after(char const*&, char*&, bool)' API_utiltyFunctions.cpp:(.text+0x17e): undefined reference to `boost::iostreams::zlib_error::check(int)' API_utiltyFunctions.cpp:(.text+0x185): undefined reference to `boost::iostreams::zlib::stream_end' The boost portion of my linker line is: -L[ path to boost 1.69] \ -lboost_random-1_69 \ -lboost_program_options-1_69 \ -lboost_date_time-1_69 \ -lboost_chrono-1_69 \ -lboost_regex-1_69 \ -lboost_thread-1_69 \ -lboost_exception-1_69 \ -lboost_filesystem-1_69 \ -lboost_system-1_69 \ -lboost_iostreams-1_69 -lrt -lbz2 -lz -lm Any help would be appreciate. Weirdly if I revert back to boost 1.66, I don't have a problem. I also tested this compilation against boost 1.70 and I get the same problem. I do compile boost statically with shared runtime libraries and threads. Respectfully, Danny K

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[variant2] Acceptance conditions met - Targeted for 1.71.0
by Michael Caisse 16 May '19

16 May '19

Peter Dimov has updated the Variant2 library based on review acceptance criteria. I have reviewed the changes and "OK" Variant2 to be included as a Boost library. My understanding is that Peter is targeting Variant2 to be available in the 1.71.0 release. Congratulations Peter! Thank you for your quick work in updating the library based on the review feedback. -- Michael Caisse Ciere Consulting ciere.com

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Building boost 1_70_0 with PGI 18.5 on CentOS 7
by Christopher Harrop - NOAA Affiliate 16 May '19

16 May '19

Hi, I am having trouble building Boost 1_70_0 with PGI 18.5 on a Linux CentOS 7 system, and I am wondering if anyone has suggestions about how to get it working. I spent some time searching online for answers, but didn’t find anything recent that applied to my problem. I am a novice with boost, and so am not sure where to start digging for solutions. I have no issues with GCC or Intel compilers. My procedure, after I untar and cd into the boost directory, is as follows: ./bootstrap.sh --with-toolset=pgi —prefix=/path/to/install/boost export BUILD_TYPE=complete export LIBRARY_NAME=versioned export LIBRARY_TARGETS=shared,static ./b2 -j 12 install --build-type=${BUILD_TYPE} --layout=${LIBRARY_NAME} --target=${LIBRARY_TARGETS} This procedure appears to work fine for the intel-linux and gcc toolsets. But, for pgi, I get this: ==================================== +./bootstrap.sh --with-toolset=pgi --prefix=/path/to/install/boost Building Boost.Build engine with toolset pgi... tools/build/src/engine/bin.linuxx86_64/b2 Detecting Python version... 2.7 Detecting Python root... /usr Unicode/ICU support for Boost.Regex?... /usr Generating Boost.Build configuration in project-config.jam for pgi... Bootstrapping is done. To build, run: ./b2 To generate header files, run: ./b2 headers To adjust configuration, edit 'project-config.jam'. Further information: - Command line help: ./b2 --help - Getting started guide: http://www.boost.org/more/getting_started/unix-variants.html - Boost.Build documentation: http://www.boost.org/build/ + export BUILD_TYPE=complete + BUILD_TYPE=complete + export LIBRARY_NAME=versioned + LIBRARY_NAME=versioned + export LIBRARY_TARGETS=shared,static + LIBRARY_TARGETS=shared,static + ./b2 -j 12 install --build-type=complete --layout=versioned --target=shared,static Performing configuration checks - default address-model : none - default architecture : none /scratch4/BMC/gsd-hpcs/Christopher.W.Harrop/bass-develop/build/boost/1.70.0/pgi/18.5/tools/build/src/tools/common.jam:977: in toolset-tag *** argument error * rule numbers.less ( n1 n2 ) * called with: ( 4 ) * missing argument n2 ==================================== Based on some suggestions I found online from others having similar errors, I edited tools/build/src/tools/common.jam to comment out these lines (977-980): # From GCC 5, versioning changes and minor becomes patch # if $(tag) = gcc && [ numbers.less 4 $(version[1]) ] # { # version = $(version[1]) ; # } This results in the following failure, which I’ve truncated because it’s really long: ==================================== + ./bootstrap.sh --with-toolset=pgi --prefix=/scratch4/BMC/gsd-hpcs/Christopher.W.Harrop/bass-develop/opt/boost/1.70.0/pgi/18.5 Building Boost.Build engine with toolset pgi... tools/build/src/engine/bin.linuxx86_64/b2 Detecting Python version... 2.7 Detecting Python root... /usr Unicode/ICU support for Boost.Regex?... /usr Generating Boost.Build configuration in project-config.jam for pgi... Bootstrapping is done. To build, run: ./b2 To generate header files, run: ./b2 headers To adjust configuration, edit 'project-config.jam'. Further information: - Command line help: ./b2 --help - Getting started guide: http://www.boost.org/more/getting_started/unix-variants.html - Boost.Build documentation: http://www.boost.org/build/ + export BUILD_TYPE=complete + BUILD_TYPE=complete + export LIBRARY_NAME=versioned + LIBRARY_NAME=versioned + export LIBRARY_TARGETS=shared,static + LIBRARY_TARGETS=shared,static + ./b2 -j 12 install --build-type=complete --layout=versioned --target=shared,static Performing configuration checks - default address-model : none - default architecture : none error: No best alternative for libs/context/build/asm_sources next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>elf <threading>multi <toolset>qcc not matched next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>mach-o <threading>multi <toolset>clang not matched next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>aapcs <address-model>32 <architecture>arm <binary-format>pe <threading>multi <toolset>msvc not matched next alternative: required properties: <abi>aapcs <address-model>64 <architecture>arm <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>aapcs <address-model>64 <architecture>arm <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>aapcs <address-model>64 <architecture>arm <binary-format>mach-o <threading>multi <toolset>clang not matched next alternative: required properties: <abi>aapcs <address-model>64 <architecture>arm <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>o32 <address-model>32 <architecture>mips1 <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>o32 <address-model>32 <architecture>mips1 <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>n64 <address-model>64 <architecture>mips1 <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>n64 <address-model>64 <architecture>mips1 <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>xcoff <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>power <binary-format>xcoff <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>mach-o <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>xcoff <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>power <binary-format>xcoff <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32_64 <architecture>power <binary-format>mach-o <threading>multi not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>elf <threading>multi <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>mach-o <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>32 <architecture>x86 <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <threading>multi <toolset>clang not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <threading>multi <toolset>clang-win not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <threading>multi <toolset>intel not matched next alternative: required properties: <abi>ms <address-model>32 <architecture>x86 <binary-format>pe <threading>multi <toolset>msvc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <threading>multi <toolset>clang not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <threading>multi <toolset>darwin not matched next alternative: required properties: <abi>sysv <address-model>64 <architecture>x86 <binary-format>mach-o <threading>multi <toolset>intel not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <threading>multi <toolset>clang not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <threading>multi <toolset>clang-win not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <threading>multi <toolset>intel not matched next alternative: required properties: <abi>ms <address-model>64 <architecture>x86 <binary-format>pe <threading>multi <toolset>msvc not matched next alternative: required properties: <abi>x32 <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>clang not matched next alternative: required properties: <abi>x32 <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>gcc not matched next alternative: required properties: <abi>x32 <address-model>64 <architecture>x86 <binary-format>elf <threading>multi <toolset>intel not matched next alternative: required properties: <abi>sysv <address-model>32_64 <architecture>x86 <binary-format>mach-o <threading>multi not matched next alternative: required properties: <abi>sysv <architecture>combined <binary-format>mach-o <threading>multi not matched - C++11 mutex : no - lockfree boost::atomic_flag : no - Boost.Config Feature Check: cxx11_auto_declarations : no - Boost.Config Feature Check: cxx11_constexpr : no - Boost.Config Feature Check: cxx11_defaulted_functions : no - Boost.Config Feature Check: cxx11_final : no - Boost.Config Feature Check: cxx11_hdr_mutex : no - Boost.Config Feature Check: cxx11_hdr_tuple : no - Boost.Config Feature Check: cxx11_lambdas : no - Boost.Config Feature Check: cxx11_noexcept : no - Boost.Config Feature Check: cxx11_nullptr : no - Boost.Config Feature Check: cxx11_rvalue_references : no - Boost.Config Feature Check: cxx11_template_aliases : no - Boost.Config Feature Check: cxx11_thread_local : no - Boost.Config Feature Check: cxx11_variadic_templates : no - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : no - bzip2 : no - lzma : no - zstd : no - iconv (libc) : no - iconv (separate) : no - icu : no - icu (lib64) : no - Boost.Locale needs either iconv or ICU library to be built. - Boost.Locale needs either iconv or ICU library to be built. - native-atomic-int32-supported : no - native-syslog-supported : no - pthread-supports-robust-mutexes : no - x86 : no - arm : no - mips1 : no - power : no - sparc : no - gcc visibility : no - long double support : no warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - libbacktrace builds : no - addr2line builds : no - WinDbg builds : no - WinDbgCached builds : no - BOOST_COMP_GNUC >= 4.3.0 : no error: No best alternative for libs/context/build/asm_sources ### similar messages to the above repeat several times and I’ve left it out for clarity and length, then output continues below ### Component configuration: - atomic : building - chrono : building - container : building - context : building - contract : building - coroutine : building - date_time : building - exception : building - fiber : building - filesystem : building - graph : building - graph_parallel : building - headers : building - iostreams : building - locale : building - log : building - math : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - stacktrace : building - system : building - test : building - thread : building - timer : building - type_erasure : building - wave : building ...patience... ...patience... ...patience... ...patience... ...patience... ...found 45809 targets... ...updating 17951 targets... gcc.compile.c++ bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/posix_api.o /bin/sh: line 1: -fvisibility-inlines-hidden: command not found -fvisibility-inlines-hidden -fPIC -pthread -O0 -fno-inline -Wall -g -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_REGEX_DYN_LINK=1 -I"." -c -o "bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/posix_api.o" "libs/regex/build/../src/posix_api.cpp" ...failed gcc.compile.c++ bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/posix_api.o... gcc.compile.c++ bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/c_regex_traits.o /bin/sh: line 1: -fvisibility-inlines-hidden: command not found -fvisibility-inlines-hidden -fPIC -pthread -O0 -fno-inline -Wall -g -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_REGEX_DYN_LINK=1 -I"." -c -o "bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/c_regex_traits.o" "libs/regex/build/../src/c_regex_traits.cpp" ...failed gcc.compile.c++ bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/c_regex_traits.o... gcc.compile.c++ bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/instances.o /bin/sh: line 1: -fvisibility-inlines-hidden: command not found -fvisibility-inlines-hidden -fPIC -pthread -O0 -fno-inline -Wall -g -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_REGEX_DYN_LINK=1 -I"." -c -o "bin.v2/libs/regex/build/gcc/debug/threading-multi/visibility-hidden/instances.o" "libs/regex/build/../src/instances.cpp" ==================================== Chris ----------------------------------------------------------------------------------------------------------- Christopher W. Harrop email: christopher.w.harrop(a)noaa.gov <mailto:christopher.w.harrop@noaa.gov> Global Systems Division voice: (303) 497-6808 <tel:%28303%29%20497-6808> NOAA Earth System Research Laboratory fax: (303) 497-7259 <tel:%28303%29%20497-7259> 325 Broadway R/GSD2 Boulder, CO 80303

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[stacktrace]stacktrace print nothing on x86.
by Hao Jiang 16 May '19

16 May '19

Hello everyone, I found boost::stacktrace print no information on my machine in RELEASE mode when target is x86, i.e. the size of stacktrace is zero. But if target switched to x64, stacktrace worked fine. Is anyone knows the reason? OS: Windows 7(64) Compiler: MSVC 14 Boost ver. :1.67/1.69 Stacktrace config: BOOST_STACKTRACE_USE_WINDBG(_CACHED) Thanks, Hao Jiang.

1 0

Boost Graph write_grahml - wrong source- and target-ID's in edge of XML-File
by lila 13 May '19

13 May '19

Hi there, I want to create an xml-file out of my Graph... So I'm using the write_graphml Function with dynamic_properties. Everything is fine, I get a file, but there are wrong source- and target- ID's in the edge structs ... Here an example: <node id="n1"> <data key="key0">vertex_7</data> <data key="key2">bf88aa63-bff1-5c04-8daf-37a5e31981f6</data> <data key="key6">12.5</data> <data key="key7">7.5</data> </node> <edge id="e1" source="n1" target="n2"> <data key="key1">edge_4_5</data> <data key="key3">26c512cb-46d8-5eb5-8021-2aac9f492227</data> <data key="key4">45844430-f1ea-5355-b7ce-eb566fe89256</data> <data key="key5">ecac63d6-e531-5ce8-9578-13cb63d040de</data> </edge> In the edge there is the wrong source-ID - it should be the ID of Vertex 4 (source="n0") not 7 (source="n1") My Graph: struct vertex { float x; float y; string name; string uuid; }; struct edge { string source_v_uuid; //startpoint uuid string target_v_uuid; //endpoint uuid string name; // name - edge_from_src-Vertex_to_dest-Vertex string uuid; }; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, vertex, edge> myGraph; And my Properties: boost::dynamic_properties dyn_p; // fill vertex properties dyn_p.property("name", get(&vertex::name, graph)); dyn_p.property("x-value", get(&vertex::x, graph)); dyn_p.property("y-value", get(&vertex::y, graph)); dyn_p.property("uuid", get(&vertex::uuid, graph)); // fill edge properties dyn_p.property("name", get(&edge::name, graph)); dyn_p.property("v-src-uuid", get(&edge::source_v_uuid, graph)); dyn_p.property("v-dest-uuid", get(&edge::source_v_uuid, graph)); dyn_p.property("uuid", get(&edge::uuid, graph)); write_graphml(ofs, graph, dyn_p, true); I tried to create a property map by myself to set the UUID as the (vertex (source/target)) -ID's, but that changed nothing, there are still wrong source- and target- ID's in the edge struct. auto map = get(&vertex2::uuid, graph); write_graphml(ofs, graph, map, dyn_p, true); Can anybody help me? Or even give me a hint to figure out what is going wrong? -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html

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[variant2] Review Results
by Michael Caisse 11 May '19

11 May '19

First, I would like to apologize to Peter and the those who took time to review Boost.Variant2 for the slow turn-around of a result. Thank you Peter for producing and submitting such a high-quality library for review. The code has been a pleasure to read and review. Thank you to the reviewers! Your participation in the process is what makes Boost libraries high-quality. I personally appreciate the time and effort that each of you have put into this review. ------------- Result ------------- Boost.Variant2 will be ACCEPTED after the following changes are made. An additional review will not be required. - The library will implement the strong guarantee: - If all alternatives have nothrow move, single buffer - else, double buffer - Improved documentation: - Addition of a tutorial - Addition of design motivation - Peter has indicated that triviality propagation will come in a future version. The initial Boost release need not support triviality propagation. - Expected will not be included but may be submitted for review at another time. ---------------- Review Verdicts ---------------- The following people provided reviews. Reject ---------- Andrezj Krzemienski Antony Polukhin Jan Herrmann Accept ---------- Emil Dotchevski Gavin Lambert Phil Endecott Conditionally Accept -------- Bjorn Reese Andrey Semashev Damian Jarek Niall Douglas Andrezj and Antony’s rejections were based on not having a valueless-by-exception state. Neither saw the selected design space worth considering and each believed the trade-off was dangerous for users. The Conditional Acceptance reviews voiced the following: - Strong preference for the strong guarantee (and therefore no need to provide “surprising” behaviour for the state after an exception.) - Improved documentation containing both tutorial and motivation sections. - Triviality propagation of the variant types. - Accepted without expected being contained. -------------- Some Thoughts -------------- There was a good amount of healthy discussion on the Developer Mail List concerning Variant2. I want to thank all of the participants for engaging with civility and keeping to the technical merits despite the galvanized opinions concerning valueless-by-exception and the basic exception guarantee. Over the past couple weeks I have re-read all of the discussion threads 3 or 4 times. While some people didn’t find value in the exchanges, this level of engagement about design trade-offs is one of the attributes that sets Boost reviews apart. They are not merely reviews discussing the quality of implementation but also the intricacies of design choices within the constraints and consistency of the language. When reviewers articulate their opinions the entire community learns and grows. The trade-offs that Peter made seem dangerous to some yet the exact correct formulation for others. There are even standard library implementers that don’t agree with std::variant’s valueless-by-exception. A high-quality variant that provides the strong exception guarantee is a type that has been missing from the programmer toolbox. Variant2 provides this. I will make an additional announcement to the community when the conditions for acceptance have been met. Thank you all for making Boost better! michael -- Michael Caisse Ciere Consulting ciere.com -- Michael Caisse Ciere Consulting ciere.com

1 0

filesystem::path crash on Windows when dealing with umlauts ( üëï )
by Gonzalo Garramuño 09 May '19

09 May '19

I am getting a crash on Windows when passing a path that contains umlauts (like sampëüö ) to the path constructor. I tried boost 1.69 and boost 1.60. Here's the code I am using: namespace fs = boost::filesystem; const char* tmp = setlocale(LC_ALL, N_("")); // Create and install global locale std::locale::global(boost::locale::generator().generate( N_("") )); // Make boost.filesystem use it fs::path::imbue(std::locale()); if ( !tmp ) tmp = setlocale( LC_ALL, NULL ); std::string program = argv[0]; fs::path file = fs::path( program ); // CRASH -- Gonzalo Garramuño

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A property_tree like structure where key is also value?
by Jeanette C. 05 May '19

05 May '19

Hey hey, I need a hirarchical data representation in my program, which is well modelled by boost.property_tree, but my keys will also be my values. The tree will have a fixed depth, all keys/values are std::string and I expect maybe a few hundred leaves and maybe a hundred or so nodes in between. Is it worth looking for a different structure at all, considering that the program is designed for desktop systems? If so: is there another Boost library that would serve me better? Best wishes and thanks for any tips, Jeanette -- * Website: http://juliencoder.de - for summer is a state of sound * SoundCloud: https://soundcloud.com/jeanette_c * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g * GitHub: https://github.com/jeanette-c * Twitter: https://twitter.com/jeanette_c_s I'm not that innocent... <3 (Britney Spears)

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[Boost.Asio coroutines] Question about HTTPServer4 examples
by daniil＠daniil.it 01 May '19

01 May '19

1 1

Using Boost 1.63 and 1.66 together with GNU unique global objects
by Jamie Jason 30 Apr '19

30 Apr '19

Apologies if this is a newbie question, but I have done my best to search Google, etc., and haven't been able to find a solution. The project I am working on uses Boost 1.63 statically linked and a third-party shared library that uses Boost 1.66 statically linked on CentOS 7. For reasons that are beyond my control, these are the versions that must be used. I am running into a problem with g++ 4.5.8 and the GNU extension to ELF for unique global symbols. Take as example the function get_netdb_category() in boost/asio/impl/error.ipp. The function has a static boost::asio::error::detail::netdb_category object that it returns a const reference to. When I use nm to inspect the main executable the symbol appears in the data segment and the type for boost::asio::error::detail::netdb_category()::instance is "u", which indicates that the compiler has marked this as a globally-unique symbol. The problem occurs when the loader loads the third-party shared library. Because the symbol boost::asio::error::detail::netdb_category()::instance has been marked as unique in the shared library as well (verified by running readelf on the .so), the loader decides that it will simply use the one from the executable. Because the shared library's version of the object is larger than the executable's version, when it is constructed it overwrites the 16 bytes beyond the end of the executable's object, trashing the contents of the data segment that were there previously. I tried using the -fno-gnu-unique flag when compiling our executable, but that doesn't fix the problem - it marks the symbol as weak in the main executable, but the shared library, because I cannot re-compile, still has the symbol marked as unique. I tried using dlopen with RTLD_LOCAL and that fixes the problem of overwriting the main executable's memory, however the corresponding symbols in the shared library have pointers back into the main executable's data segment (where the corresponding netdb_category static lives), which means that when if the shared library accesses these objects it will be following invalid pointers as it will overlay a larger v1.66 object onto a smaller v1.63 object. Has anyone encountered a problem like this? And, if so, did you find a good solution? Much thanks, Jamie

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