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Iterate intrusive list without container?
by John W 24 Oct '21

24 Oct '21

With a traditional "hand-rolled" doubly-linked list, if you have a reference to a Node, you can traverse from that node to the end of the list easily. Just check for "pNext == NULL" to know when you're at the end. You don't need any reference to the owning "list container" object. However, I can't seem to accomplish the same with boost::intrusive::list. Traversal with an intrusive::list's iterator is done STL-style, and for that you need to compare to the container's ".end()" value. I am aware of the "s_iterator_to" function[1], which can statically get an iterator from a node, but there doesn't seem to be any way to statically get a usable ".end()" value to compare to. There is also "container_from_end_iterator"[2], which gives the container if you have "end()" available already — not quite what I want, but I guess shows that end() is intimately tied to the container. I also notice that if I have an iterator to the last element in a list, and I increment it (++iterator), no error is given. But if I try to dereference it, I get garbage data. Peeking into the implementation, from what I can tell, boost::intrusive::list is actually a circular list, with a special "root node" that the container owns, and which represents the "end". So, iterating beyond the end gives you that root node. I guess my questions are: (1) Is my analysis above correct? I feel I might have missed something wading through all the templates, and the docs I've found don't discuss these implementation details. (2) Is there any way to accomplish what I want? That is: iterating from an arbitrary node to the end of the list, *without* a reference to the owning container? (3) [aside] If the answer to the above is "no", does anyone know what the rationale is for this design choice? It seems odd that such a basic feature of a traditional hand-made intrusive list would be dropped if there were no benefit. Thanks -John [1] https://github.com/boostorg/intrusive/blob/f44b0102b4ee9acf7b0304b3f5b27dde… [2] https://github.com/boostorg/intrusive/blob/f44b0102b4ee9acf7b0304b3f5b27dde…

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Conversion from exception_ptr to shared_ptr
by rajesh daggumati 19 Oct '21

19 Oct '21

HI, please help me to solve below issue. Shared pointers are used in my code. class Exception : public virtual std::exception,public virtual boost::exception { --- }; class ExceptionTestException : public Exception { --- }; boost::shared_ptr<Exception> exceptionptr_t; try { Boost_Throw_function(ExceptionTestException("Hiii")); } catch(...) { boost::exception_ptr exceptionptr = boost::current_exception(); try { boost::rethrow(exceptionptr) } catch(boost::exception &e) { //here i need to assign this 'e' to shared pointer but this e is not in heap so then how to assign this e to sharedptr(exceptionptr_t). 1 way is : boost::exception *ep = new ExceptionTestException(e); exceptionptr_t(ep); here we know that exception_ptr is having ExceptionTestException but in some cases, we dont know which type of excepiton we have in exception_ptr in runtime. then how to assign to shared_ptr

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Version 77 download not a bz2 file
by Chris 16 Oct '21

16 Oct '21

Trying to use version 77 I get a "wrong checksum" message: Failed to download sources: module boost: Wrong sha256 checksum for boost_1_77_0.tar.bz2, expected "fc9f85fc030e233142908241af7a846e60630aa7388de9a5fafb1f3a26840854", was "4ffd1325229da00455ae95a68de976d053e46315628ffcd57a433238e74e7eab" If I change the checksum in the download command to that shown above I get a "not a .bz2 file" message. Chris

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Thread crash in destructor
by Alexander Carôt 08 Oct '21

08 Oct '21

Hi all, I had been using an old boost system and boost thread lib for a couple of years without upgrading it since approx. 2014. With this old lib the following (simplified) code works fine on OSX: #include "test.h" test::test() { boost::thread::attributes attrs; /// START TRACEROUTE THREAD #if defined(BOOST_THREAD_PLATFORM_WIN32) res = SetThreadPriority(attrs.native_handle(), THREAD_PRIORITY_NORMAL); #elif defined(BOOST_THREAD_PLATFORM_PTHREAD) pthread_attr_setschedpolicy(attrs.native_handle(), SCHED_FIFO); #endif tracerouteThread = boost::thread( attrs, boost::bind(&test::performTraceroute, this)); } void test::performTraceroute() { cout << "START TRACEROUTE" << endl; string exec = ""; cout << "DO FURTHER STUFF BUT THIS IS JUST A DEMO ..." << endl; cout << "THREAD OVER" << endl; } Using the current boost 1_77 still does execute the thread but then it crashes within the destructor. Adding tracerouteThread.join() or .detach() after launching the thread does not help either. Can anyone help how to resolve this issue ? Thanks a lot in advance, best Alex -- http://www.carot.de Email : Alexander(a)Carot.de Tel.: +49 (0)177 5719797

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Re: [Boost-users] Thread crash in destructor
by Alexander Carôt 08 Oct '21

08 Oct '21

see below – scanning my own info I realized: >>Thread 4 Crashed: >>0 libboost_thread.dylib 0x000000010e4a4570 tls_destructor + 96 ... that it linked to a dynamic lib which I did not intend to – I am using a static lib and this made me conclude that I had a path issue so it eventually linked to a wrong lib which eventually caused the issue. After fixing my paths the issue is resolved and it works perfectly fine even with the latest 1_77 Sorry for the confusion and thanks for your help ! Now it would be nice to focus on the thread priority which might possibly be wrong as well. Best Alex Hej Juan, thanks for the quick response ! >>Are you sure detach() and join() do not help? Yes, I checked it several times. I put either tracerouteThread.join() or tracerouteThread.dispatch() right after launching it but it resultet in the same effect. Please find the OSX-report here – thread 4 is the one that crashes (just in case: My app uses Qt): Thread 0:: Dispatch queue: com.apple.main-thread 0 libsystem_kernel.dylib 0x00007fff69658dfa mach_msg_trap + 10 1 libsystem_kernel.dylib 0x00007fff69659170 mach_msg + 60 2 com.apple.CoreServices.CarbonCore 0x00007fff30844d1d _scsclient_CacheableGetDataWithStringKey + 207 3 com.apple.CoreServices.CarbonCore 0x00007fff30844c44 RemoteCacheable::GetWithStringKey(unsigned int, char const*, unsigned long*, unsigned int*) + 70 4 com.apple.CoreServices.CarbonCore 0x00007fff30844ae6 _CSGetNamedData + 98 5 com.apple.AppKit 0x00007fff2c6b5e19 _NSPersistentUIGetShmem + 115 6 com.apple.AppKit 0x00007fff2c6b59c0 _NSPersistentUIEstablishTalagentCommunication + 113 7 com.apple.AppKit 0x00007fff2c6b4d91 -[NSApplication finishLaunching] + 66 8 com.apple.AppKit 0x00007fff2c6b4a20 -[NSApplication run] + 244 9 libqcocoa.dylib 0x000000010fcf2f18 QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 2120 (qcocoaeventdispatcher.mm:431) 10 org.qt-project.QtCore 0x000000010f637d36 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 470 (qeventloop.cpp:232) 11 org.qt-project.QtCore 0x000000010f62f092 QCoreApplication::exec() + 130 12 com.yourcompany.soundjack 0x000000010dfb6b41 main + 2817 13 libdyld.dylib 0x00007fff69517cc9 start + 1 Thread 1: 0 libsystem_pthread.dylib 0x00007fff69717b68 start_wqthread + 0 Thread 2: 0 libsystem_pthread.dylib 0x00007fff69717b68 start_wqthread + 0 Thread 3: 0 libsystem_pthread.dylib 0x00007fff69717b68 start_wqthread + 0 Thread 4 Crashed: 0 libboost_thread.dylib 0x000000010e4a4570 tls_destructor + 96 1 libboost_thread.dylib 0x000000010e4a5784 thread_proxy + 148 2 libsystem_pthread.dylib 0x00007fff6971c109 _pthread_start + 148 3 libsystem_pthread.dylib 0x00007fff69717b8b thread_start + 15 Thread 4 crashed with X86 Thread State (64-bit): rax: 0x00000010018da37d rbx: 0x00000010018da37d rcx: 0x0000000000000008 rdx: 0x00007fef2dd18320 rdi: 0x00007fef2dd18180 rsi: 0x00000000000120a8 rbp: 0x000070000346ff70 rsp: 0x000070000346ff30 r8: 0x00000000000130a8 r9: 0x0000000000000000 r10: 0x00007fff8fc0dbf8 r11: 0x00007fff8fc0dbf0 r12: 0x00007fef2dd18180 r13: 0x0000000000000000 r14: 0x00007fef2dd18328 r15: 0x0000000000000000 rip: 0x000000010e4a4570 rfl: 0x0000000000010206 cr2: 0x00000010018da385 -- http://www.carot.de Email : Alexander(a)Carot.de Tel.: +49 (0)177 5719797 > Gesendet: Donnerstag, 07. Oktober 2021 um 21:06 Uhr > Von: "Juan Ramírez" <jramirez.uy(a)gmail.com> > An: boost-users(a)lists.boost.org > Cc: "Alexander Carôt" <alexander_carot(a)gmx.net> > Betreff: Re: [Boost-users] Thread crash in destructor > > The behavior changed in BOOST_THREAD_VERSION 3 (which is default in > boost 1.77). Are you sure detach() and join() do not help? > > Can you provide a call stack? > > On 10/7/21 06:09, Alexander Carôt via Boost-users wrote: > > Hi all, > > > > I had been using an old boost system and boost thread lib for a couple of years without upgrading it since approx. 2014. With this old lib the following (simplified) code works fine on OSX: > > > > #include "test.h" > > > > test::test() { > > boost::thread::attributes attrs; > > > > /// START TRACEROUTE THREAD > > #if defined(BOOST_THREAD_PLATFORM_WIN32) > > res = > > SetThreadPriority(attrs.native_handle(), THREAD_PRIORITY_NORMAL); > > #elif defined(BOOST_THREAD_PLATFORM_PTHREAD) > > pthread_attr_setschedpolicy(attrs.native_handle(), SCHED_FIFO); > > #endif > > tracerouteThread = boost::thread( > > attrs, boost::bind(&test::performTraceroute, this)); > > } > > > > void test::performTraceroute() { > > cout << "START TRACEROUTE" << endl; > > > > string exec = ""; > > cout << "DO FURTHER STUFF BUT THIS IS JUST A DEMO ..." << endl; > > cout << "THREAD OVER" << endl; > > } > > > > Using the current boost 1_77 still does execute the thread but then it crashes within the destructor. Adding > > > > tracerouteThread.join() or .detach() after launching the thread does not help either. > > > > Can anyone help how to resolve this issue ? > > > > Thanks a lot in advance, > > best > > > > Alex > > > > -- > > http://www.carot.de > > Email : Alexander(a)Carot.de > > Tel.: +49 (0)177 5719797 > > > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > https://lists.boost.org/mailman/listinfo.cgi/boost-users > > >

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Build issue on OSX boost 1.77 json lib is not build.
by Jiri Hoogland 07 Oct '21

07 Oct '21

Hi, I have a mysterious issue where on OSX I try to build boost 1.77 with among others the json component but it is not built. On linux there is no issue. The same script builds everything fine. Has anybody come across this by any chance ? I could not find anything from a search on the net. Thanks, Jiri Below are more details. Using the commands listed below in the OSX case, the json lib is not built, and on Linux it is. Switching on more verbosity and using the -a -q -d 5 shows that json is in the output, but not clear why it is not built. This also seems to be the case for 1.76, we tried this on multiple machines. export ZLIB_DIR=/tmp/zlib-1.2.11 export BZIP2_DIR=/tmp/bzip2-1.0.6 ./b2 link=static variant=release cxxflags="-fPIC" cflags="-fPIC" --build-type=minimal -j8 --build-dir=/tmp/boost/build stage --stagedir=/tmp/boost/stage -sBZIP2_SOURCE=${BZIP2_DIR} -sZLIB_SOURCE= ${ZLIB_DIR} -sNO_ZSTD=1 --with-filesystem --with-iostreams --with-regex --with-system --with-json ls -l /tmp/boost/stage/lib # osx 10.15.7 clang 12 cmake 3.21.3 $ uname -a Darwin vola-imac-jiri.local 19.6.0 Darwin Kernel Version 19.6.0: Tue Aug 24 20:28:00 PDT 2021; root:xnu-6153.141.40~1/RELEASE_X86_64 x86_64 $ c++ --version Apple clang version 12.0.0 (clang-1200.0.32.29) Target: x86_64-apple-darwin19.6.0 Thread model: posix InstalledDir: /Library/Developer/CommandLineTools/usr/bin $ cmake --version cmake version 3.21.3 $ ll /tmp/boost/stage/lib total 2168 drwxr-xr-x 12 jiri wheel 384 Oct 4 09:10 cmake/ -rw-r--r-- 1 jiri wheel 42688 Oct 4 09:10 libboost_atomic.a -rw-r--r-- 1 jiri wheel 85696 Oct 4 09:10 libboost_bzip2.a -rw-r--r-- 1 jiri wheel 207752 Oct 4 09:10 libboost_filesystem.a -rw-r--r-- 1 jiri wheel 156984 Oct 4 09:10 libboost_iostreams.a -rw-r--r-- 1 jiri wheel 486752 Oct 4 09:10 libboost_regex.a -rw-r--r-- 1 jiri wheel 880 Oct 4 09:10 libboost_system.a -rw-r--r-- 1 jiri wheel 116864 Oct 4 09:10 libboost_zlib.a $ ssh docs # lin gcc10 $ uname -a Linux 09964f3495a3 5.10.25-linuxkit #1 SMP Tue Mar 23 09:27:39 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux $ c++ --version c++ (GCC) 10.3.0 Copyright (C) 2020 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ cmake --version cmake version 3.20.5 $ ls -l /tmp/boost/stage/lib total 2316 drwxr-xr-x 13 vola wheel 4096 Oct 4 12:19 cmake -rw-r--r-- 1 vola wheel 14472 Oct 4 12:19 libboost_atomic.a -rw-r--r-- 1 vola wheel 171174 Oct 4 12:19 libboost_container.a -rw-r--r-- 1 vola wheel 516560 Oct 4 12:19 libboost_filesystem.a -rw-r--r-- 1 vola wheel 226418 Oct 4 12:19 libboost_iostreams.a *-rw-r--r-- 1 vola wheel 478604 Oct 4 12:19 libboost_json.a* -rw-r--r-- 1 vola wheel 797230 Oct 4 12:19 libboost_regex.a -rw-r--r-- 1 vola wheel 1412 Oct 4 12:19 libboost_system.a -rw-r--r-- 1 vola wheel 146394 Oct 4 12:19 libboost_zlib.a

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[Boost.Asio] Segmentation fault when ::getaddrinfo() returns EAI_SYSTEM without system error code set (errno = 0) - is this a bug?
by Nils Frielinghaus 04 Oct '21

04 Oct '21

Hello Boost users, I experienced a segmentation fault inside Boost in the following scenario: o There was an illegal DNS entry o When resolving that illegal DNS entry on a Yocto-based embedded Linux distribution, ::getaddrinfo() returned with the error code EAI_SYSTEM but errno was set to 0 o The function translate_addrinfo_error(int) in boost/asio/detail/impl/socket_ops.ipp translates this into boost::system::error_code(0, boost::asio::error::get_system_category()) o This is then interpreted as a success by the calling function and the other output parameters of ::getaddrinfo() are accessed which resulted in the segmentation fault My question would be whether this should be considered a bug in the Boost ASIO library? One could argue that the system should not return EAI_SYSTEM with errno not being set properly. But one could also argue that returning EAI_SYSTEM indicates that something went wrong and that the output parameters are not to be accessed. Nils ------ Nils Frielinghaus

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Problem understanding 'boost::intrusive::list_member_hook<>'
by John Emmas 14 Sep '21

14 Sep '21

I'm in the early stages of trying to understand boost::intrusive::list' so forgive me if I'm just doing something stupid!! Using VS2019 I wrote a small demo app which uses 'boost::intrusive::list_base_hook<>':- #include <boost/intrusive/list.hpp> #include <string> #include <iostream> using namespace std; class animal : public boost::intrusive::list_base_hook<> { public: animal (string n, int l) : name{move(n)}, legs{l} {} string name; int legs; }; using animal_list = boost::intrusive::list<animal>; template<typename T> void print_list (const boost::intrusive::list<T>& elem) { for (const T& a : elem) cout << "A " << a.name << " has " << a.legs << " legs" << '\n'; } int main() { animal a1{"dog", 4}; animal a2{"spider", 6}; animal a3{"budgie", 2}; animal_list animals; animals.push_back(a1); animals.push_back(a2); animals.push_back(a3); print_list (animals); return 0; } Everything runs fine and I see the expected output but I've noticed that some other developers use something called a 'list_member_hook' rather than my 'list_base_hook' - so class animal would look like this:- class animal { public: animal (string n, int l) : name{move(n)}, legs{l} {} string name; int legs; boost::intrusive::list_member_hook<> _animal_hook; }; and then later on in the program there'd be a couple of lines looking something like this:- typedef boost::intrusive::member_hook<animal, boost::intrusive::list_member_hook<>, &animal::_animal_hook> AnimalHookOption; typedef boost::intrusive::list<animal, AnimalHookOption> Animals; But when I try that here, VS2019 throws up this compiler error:- error C2039: 'default_list_hook': is not a member of 'animal' Can anyone explain what I'm doing wrong?? John

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Support end date of boost version ,1.76.0
by rajesh daggumati 08 Sep '21

08 Sep '21

Hi Team, When is supporting end date for boost 1.76.0. Please let me know asap. Regards, Rajesh D

2 1

Linking Problem
by Stephen P. Molnar 04 Sep '21

04 Sep '21

I have successful compiled an application on my Debian-10 platform using boost-1-67. It is an essential part of my computations chemistry pipe line. Now Debian 11 has been released. I have installed it in a VM in order to make sure that the app is compilable in Debian 11 with boost-1-74 (the Debian12 version of boost), before upgrading my Linux platform. I installed boost in /user/ilocal. The makefile is: BASE=/usr/local BOOST_VERSION=1_74_0 BOOST_INCLUDE = $(BASE)/include C_PLATFORM= -pthread GPP=g++ C_OPTIONS= -O3 -DNDEBUG BOOST_LIB_VERSION= include ../../makefile_common The test compile went well until the link stage. The process stopped with: g++ -pthread -ansi -Wno-long-long -O3 -DNDEBUG -I /usr/local/include -L/usr/local/lib -L. -o gwovina main.o cache.o coords.o current_weights.o everything.o grid.o szv_grid.o manifold.o model.o gwo.o gwo_mutate.o my_pid.o naive_non_cache.o non_cache.o parallel_gwo.o parse_pdbqt.o pdb.o quasi_newton.o quaternion.o random.o ssd.o terms.o weighted_terms.o rotamer.o -l boost_system -l boost_thread -l boost_program_options /usr/bin/ld: cannot find -lboost_system /usr/bin/ld: cannot find -lboost_thread /usr/bin/ld: cannot find -lboost_program_options collect2: error: ld returned 1 exit status make: *** [../../makefile_common:34: gwovina] Error 1 Even my limited knowledge (my original programming experience was with FORTRAN II in the early 1960's), I can see the the problem. Unfortunately, I don't know the solution. Assistance will be greatly appreciated. Thanks om advance. -- Stephen P. Molnar, Ph.D. www.molecular-modeling.net 614.312.7528 (c) Skype: smolnar1

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Comment on divide_unsigned_helper
by Neill Clift 03 Sep '21

03 Sep '21

Hi, I was trying to understand the algorithm inside the main divide routine. I struggled with this bit of code: if ((prem[r_order] <= py[y_order]) && (r_order > 0)) { double_limb_type a = (static_cast<double_limb_type>(prem[r_order]) << CppInt1::limb_bits) | prem[r_order - 1]; double_limb_type b = py[y_order]; double_limb_type v = a / b; if (v <= CppInt1::max_limb_value) { guess = static_cast<limb_type>(v); --r_order; } } I was trying to understand why we essential set guess to 1 in the case that the division is too big. I finally realized that the only way we can have v > CppInt1::max_limb_value is if we have prem[r_order] == py[y_order]. Some simple inequalities with floor can convince you of this. So in the case of equality we do an expensive divide and test when we could move the test outside like this: limb_type guess = 1; if (r_order == 0) { <-------- do this first to simplify guess = prem[0] / py[y_order]; } else if (prem[r_order] == py[y_order]) { <----------- handle it here to avoid the divide guess = 1; ... This leads to another question. Why is this line: guess = prem[0] / py[y_order]; not this line: guess = prem[0] / py[0]; Logically for division it must be the second line. In fact this loop has the invariant that r_order >= y_order. That makes sense for division. So the divisor must be py[0]. That suggests a divisor with one element and we handle that case via a special divide. So that code is not needed I believe. We end up with this: BOOST_ASSERT(r_order >= y_order && y_order >= 1); if (prem[r_order] == py[y_order]) { guess = 1; } else if (prem[r_order] < py[y_order]) { double_limb_type a = (static_cast<double_limb_type>(prem[r_order]) << CppInt1::limb_bits) | prem[r_order - 1]; double_limb_type b = py[y_order]; double_limb_type v = a / b; BOOST_ASSERT(v <= CppInt1::max_limb_value); guess = static_cast<limb_type>(v); --r_order; } else { double_limb_type a = (static_cast<double_limb_type>(prem[r_order]) << CppInt1::limb_bits) | prem[r_order - 1]; double_limb_type b = (y_order > 0) ? (static_cast<double_limb_type>(py[y_order]) << CppInt1::limb_bits) | py[y_order - 1] : (static_cast<double_limb_type>(py[y_order]) << CppInt1::limb_bits); BOOST_ASSERT(b); double_limb_type v = a / b; guess = static_cast<limb_type>(v); } BOOST_ASSERT(guess); // If the guess ever gets to zero we go on forever.... Some simple random divide tests seem to show a little over 2% improvement from doing this. Of course this could just be code layout changes. Just thinking that the 64 bit values are random would make me think this case is rare but I guess we subtract out multiples of the divisor and cause this to happen more for reasons that are hard to understand (for me anyway). I see the path hit a lot. Neill.

1 0

Jamshell query
by Mohammed Zahid 03 Sep '21

03 Sep '21

Hi, I am trying to run boost build in distributed environment by setting JAMSHELL I tried setting as environment variable and passing as command line variable -sJAMSHELL= Both didn't work https://github.com/bfgroup/b2/discussions/78 Need you guidence on how to do it. Thanks, Mohammed zahid

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3D Tree Queries
by Glenn, Rachel M 02 Sep '21

02 Sep '21

I have a question about 3D RTree spatial queries, like a cube, sphere, or something. Are there any examples of how that can be done? I know how to do it for 2D RTree. Do you recommend the regular RTREE or a is there another one to use, like an rstar, that would be better? Thanks, Rachel

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[Compute] automatically determine work group size
by Stephan Menzel 30 Aug '21

30 Aug '21

Hello everyone, I have recently made the switched an existing OpenCL application to boost compute. For reasons mostly. Now the transition went well for the most part but I struggle with one feature that appears to be missing. The determination of the local work group size. Originally the code was using clEnqueueNDRangeKernel() which has an option for the local work group size called local_work_size. When left empty, the system will determine that value itself at a small cost. Boost compute doesn't seem to have that. When I process an image for example: command_queue.enqueue_nd_range_kernel(kernel, bc::extents<2>{ 0, current_line }, bc::extents<2>{ width, height }, bc::extents<2>{ 128, 1 }); The last parameter is very hard for me to understand. I know roughly what it is and I understand it has to be dividable by 64, the total size (width * height) however has to be a multiple of it too, so there's a bunch of rules that apply and I would much rather leave that auto-determined as it was before. Leaving it bc::extents<2>{ 0, 0 } throws an assertion. So, essentially: Is there a way to leave it empty to be auto-defined? Cheers, Stephan

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boost/rational.hpp and VS2019
by John Emmas 24 Aug '21

24 Aug '21

I'm guessing this might be solvable by updating to a newer version of boost (currently I'm running ver 1.71.0) but before updating, I wondered if there might be something obvious that 'm missing.... I'm building with Visual Studio 2019 and I get a whole bunch of errors simply by adding this line to an empty source file:- #include "boost/rational.hpp" It seems to be the same 6 errors but at various different lines - i.e. these errors, over & over again:- Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(146,19): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(146,8): error C2146: syntax error: missing ';' before identifier '_mm_macc_ps' Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(147,20): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(147,9): error C2146: syntax error: missing ';' before identifier '_mm_macc_pd' Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(148,19): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ammintrin.h(148,1): error C2086: 'int __m128': redefinition I just wondered if this might ring a bell with someone? e.g. might there be some preprocesser #define that I should've defined? (or a #define that I shouldn't be defining...) Thanks for any suggestions, John

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Boost's Stage\Lib *.a Files
by Alexander Tanseco 23 Aug '21

23 Aug '21

I am running a tutorial program and I found out that in the program's build options under Linker settings/Link Libraries I can put both or either of the ff and the program compiles & runs without errors. What is the difference between the two? libboost_filesystem-mgw8-mt-d-x64-1_77.dll.a OR libboost_filesystem-mgw8-mt-x64-1_77.dll.a

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[multiprecission] Large divides layered on 128 bit divides
by Neill Clift 21 Aug '21

21 Aug '21

Hi, The architecture of cpp_int being build on 64 bit arithmetic using 128 bit double_limb_type is interesting. I have a question on the large divide (divide_unsigned_helper). It uses the upper portions of the large integers to get an estimation of the quotient. Subtracts out a multiple of that quotient and repeats. It does this in 128 bit values if available from the compiler: double_limb_type a = (static_cast<double_limb_type>(prem[r_order]) << CppInt1::limb_bits) | prem[r_order - 1]; double_limb_type b = py[y_order]; double_limb_type v = a / b; The compiler emulates this operation in the routine __udivmodti4 which itself uses an iterative approach. It seems to use a pretty basic shift and subtract algorithm mind you. As a general rule for multiprecision is it OK to layer the Knuth like algorithm D on top of each other this way. I have no idea myself but wonder if this is a known issue. I would have guessed that it made sense to do a 64 by 64 bit divide to guess the quotient and repeat. Thoughts? Thanks. Neill.

2 2

[multiprecission] some thoughts on add_unsigned.hpp
by Neill Clift 19 Aug '21

19 Aug '21

Hi, In my program I see a lot of time taken up by add/subtract_unsigned. I have a couple of thoughts on the code: Carry propagation outside the range of the smallest number can be improved: for (; i < x && carry; ++i) carry = ::boost::multiprecision::detail::addcarry_limb(carry, pa[i], 0, pr + i); Maybe this: for (; i < x && carry; ++i) carry = ::boost::multiprecision::detail::addcarry_limb(0, pa[i], 1, pr + i); This generates just an inc on my machine but unfortunately it doesn't eliminate the loads and stores. I think on average the carry chain must be small though. You have the same situation on subtract. add_unsigned and subtract_unsigned are inconsistent at the tail end after carry propagation: add_unsigned: if (i == x && carry) { // We overflowed, need to add one more limb: result.resize(x + 1, x + 1); if (result.size() > x) result.limbs()[x] = static_cast<limb_type>(1u); } else std::copy(pa + i, pa + x, pr + i); <--- if I == x we do the copy. We also do the copy even if the output and input overlap subtract_unsigned: // Any remaining digits are the same as those in pa: if ((x != i) && (pa != pr)) <-------- we do these checks here and avoid the copy std_constexpr::copy(pa + i, pa + x, pr + i); I am seeing a lot of time being used by that general copy above in add_unsigned when it can be avoided. This stuff is totally awesome and works well in my program. So thanks for working on this stuff. Neill.

2 1

Boost Installation in Codeblocks
by Alexander Tanseco 18 Aug '21

18 Aug '21

To Gavin Lambert, many thanks for your help. I finally got my program running without errors with the ff settings: Global variable Lib: c:\boost_1_77_0\stage\lib Program's build options: Linker settings/Link libraries: blank Search Directories/Compiler: $(#boost) Search Directories/Linker: $(#boost.lib).

1 0

Boost uses unoptimized subtraction because of typo in intel_intrinsics.hpp
by Neill Clift 18 Aug '21

18 Aug '21

Hi, In my program I am seeing my code use the slower (I assume) subtract_unsigned_constexpr rather than subtract_unsigned with he borrow chain handled intrinsics. This seems to be happening because of these lines in intel_intrinsics.hpp: #if defined(__clang__) && (__clang__ < 9) // We appear to crash the compiler if we try to use these intrinsics? #undef BOOST_MP_HAS_IMMINTRIN_H #endif __clang__ is not the version but just the value 1. I expect this should be the major version instead: #define __clang__ 1 #define __clang_major__ 12 #define __clang_minor__ 0 As an aside 128bit support does work in windows with clang. I have to force it on like this: #define __STRICT_ANSI__ #define BOOST_HAS_INT128 #define BOOST_MP_HAS_IMMINTRIN_H #include <boost/multiprecision/cpp_int.hpp> Thanks. Neill.

2 1

boostrap fails with intel-linux
by Alain O' Miniussi 18 Aug '21

18 Aug '21

Hi I have a C++11 compiler: [alainm@zztop boost_1_77_0]$ icpc --version icpc (ICC) 2021.3.0 20210609 Copyright (C) 1985-2021 Intel Corporation. All rights reserved. [alainm@zztop boost_1_77_0]$ I can use it to build b2: [alainm@zztop boost_1_77_0]$ icpc --version icpc (ICC) 2021.3.0 20210609 Copyright (C) 1985-2021 Intel Corporation. All rights reserved. [alainm@zztop boost_1_77_0]$ ./tools/build/src/engine/build.sh --cxx=icpc ... ### Using 'cxx' toolset. >>> Why cxx ? ... icpc (ICC) 2021.3.0 20210609 Copyright (C) 1985-2021 Intel Corporation. All rights reserved. ..... > icpc -DNDEBUG builtins.cpp class.cpp command.cpp compile.cpp constants.cpp cwd.cpp debug.cpp debugger.cpp execcmd.cpp execnt.cpp execunix.cpp filesys.cpp filent.cpp fileunix.cpp frames.cpp function.cpp glob.cpp hash.cpp hcache.cpp hdrmacro.cpp headers.cpp jam_strings.cpp jam.cpp jamgram.cpp lists.cpp make.cpp make1.cpp md5.cpp mem.cpp modules.cpp native.cpp object.cpp option.cpp output.cpp parse.cpp pathnt.cpp pathsys.cpp pathunix.cpp regexp.cpp rules.cpp scan.cpp search.cpp startup.cpp subst.cpp sysinfo.cpp timestamp.cpp variable.cpp w32_getreg.cpp modules/order.cpp modules/path.cpp modules/property-set.cpp modules/regex.cpp modules/sequence.cpp modules/set.cpp -o b2 > cp b2 bjam [alainm@zztop boost_1_77_0]$ But bootstrap.sh fails to see it: alainm@zztop boost_1_77_0]$ ./bootstrap.sh --with-toolset=intel-linux Building B2 engine.. A C++11 capable compiler is required for building the B2 engine. Toolset 'intel-linux' does not appear to support C++11. ... ** Note, the C++11 capable compiler is _only_ required for building the B2 ** engine. The B2 build system allows for using any C++ level and any other ** supported language and resource in your projects. ... You can specify the toolset as the argument, i.e.: ./build.sh [options] gcc Toolsets supported by this script are: acc, clang, como, gcc, intel-darwin, intel-linux, kcc, kylix, mipspro, pathscale, pgi, qcc, sun, sunpro, tru64cxx, vacpp ## And then a lot of comment regarding build.sh which we did not called ourselve so not very usefull Failed to build B2 build engine [alainm@zztop boost_1_77_0]$ Any idea of what went wrong ? Thanks ---- Alain Miniussi DSI, Pôles Calcul et Genie Log. Observatoire de la Côte d'Azur Tél. : +33492003009 (Mont-Gros) +33483618544 (Sophia Antipolis) +33609650665

1 0

Boost Installation in Codeblocks
by Alexander Tanseco 17 Aug '21

17 Aug '21

I successfully built Boost in my directory c:\boost_1_77_0. After which, I set up my global variable boost with base c:\boost_1_77_0. For the built-in field lib, I entered c:\boost_1_77_0\stage\lib (see attached screenshot). For the program's build options, under Linker settings/Link libraries: $(#boost.stage.lib) Under Search Directories/Compiler I entered $(#boost) and under Search Directories/Linker I entered $(#boost.stage.lib). When I built a typical Hello World program (see attached screenshot), I get an error message (see attached screenshot). Where did I go wrong? Somebody, please help.

2 1

[release]Boost 1.77.0
by Marshall Clow 14 Aug '21

14 Aug '21

Release 1.77.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains two new libraries and numerous enhancements and bug fixes for existing libraries. * Describe: A C++14 reflection library, from Peter Dimov. Provides macros for describing enumerators and struct/class members, and primitives for querying this information. * Lambda2: A C++14, dependency-free, single header lambda library, from Peter Dimov. For details, including download links, see <http://www.boost.org/users/news/version_1.77.0> You can also download directly from: <https://boostorg.jfrog.io/artifactory/main/release/1.77.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Marshall Clow, Michael Caisse, Glen Fernandes

2 1

Replace icpx with icpc
by Borchert, Christopher B ERDC-RDE-ITL-MS CIV 10 Aug '21

10 Aug '21

I'm trying to build Boost 1.76 from source on SLES 15 using Intel 19.1.3.304 (and GCC 10.2.0 underneath). Simply, how to I get b2 not to use icpx? With icpc it builds but icpx gives ./b2 toolset=intel-linux icpx: error while loading shared libraries: libimf.so: cannot open shared object file: No such file or directory I've tried everything and resorted to altering $PATH to remove icpx, which is how I know that's the problem. Thanks, Chris

3 5

[boost][multiprecision/mpc][math/quadrature] Why boost::multiprecision::exp gets stuck when evaluating complex-valued integral?
by Kirill Kudashkin 06 Aug '21

06 Aug '21

Dear all, I have encountered a problem while using Boost C++ libraries ( multiprecision/mpc.hpp, math/quadrature) which I cannot resolve. This problems appears when running the following piece of code || |#include <boost/math/constants/constants.hpp> #include <boost/math/quadrature/exp_sinh.hpp> #include <boost/multiprecision/mpc.hpp> #include <boost/multiprecision/mpfr.hpp> #include <boost/math/special_functions/fpclassify.hpp> namespace mpns = boost::multiprecision; typedef mpns::number<boost::multiprecision::mpc_complex_backend <50> > mpc_type ; typedef mpc_type::value_type mp_type ; int main() { using boost::math::constants::root_pi ; mpc_type z{mp_type(1),mp_type(1)} ; auto f = [&](mp_type x) { //actually I did not test if all these conditions are needed... if (boost::math::fpclassify<mp_type> (x) == FP_ZERO) { return mpc_type(mp_type(1)) ; }; if (boost::math::fpclassify<mp_type> (x) == FP_INFINITE) { return mpc_type(mp_type(0)) ; }; mp_type x2 = mpns::pow(x,2U) ; if (boost::math::fpclassify<mp_type> (x2) == FP_ZERO) { return mpc_type(mp_type(1)) ; }; if (boost::math::fpclassify<mp_type> (x2) == FP_INFINITE) { return mpc_type(mp_type(0)) ; }; mpc_type ex2 = mpns::exp(-z*x2) ; if (boost::math::fpclassify<mpc_type> (ex2) == FP_ZERO) { return mpc_type(mp_type(0)) ; }; return ex2 ; } ; mp_type termination = boost::math::tools::root_epsilon <mp_type> () ; mp_type error; mp_type L1; size_t max_halvings = 12; boost::math::quadrature::exp_sinh<mp_type> integrator(max_halvings) ; mpc_type res = integrator.integrate(f,termination,&error,&L1) ; mpc_type div = 2U*mpns::sqrt(z) ; mpc_type result = (mpc_type(root_pi<mp_type> ())/div) - res ; return 0; } | ||Namely, the problem appears when evaluating the exponent. The code is compiled without any problems, but hangs on computing | mpc_type ex2 = mpns::exp(-z*x2) ;| It was possible to go into the function while debugging. It crashed eventually, when the compiler reached "unable to resolve non-existing file.../src/init2.c". I let it run for a while checking the call stack. It appears that the programs is stuck atcalling ___gmpn_sub_n_coreisbr(). Or better, in the call stuck it appeared frequently. I did several tests. The real-valued version (with mpfr_backend <2000>) works without any problems. cpp_complex_backend <100> works fine, but I could not test higher precision yet, since it is much slower. I found a work-around which is not ideal. Namely, mpc_type ex2 = mpc_type(mpns::exp(x2)) ; mpc_type ezx2 = mpns::pow(ex2,-z) ; works fine with mpc_complex_backend <2000>. The lambda-function as it is declared in the code above works and yields correct numbers. The problem appears when it is called from the integrator. My system. I use openSUSE Tumbeleweed. I installed boost libraries as provided by |boost_1_76_0-gnu-mpich-hpc-devel.| Complier -> g++, cppStandard gnu+17. I check that I have all libs, e.g. libgmp, libmpc, libmpfr and etc. All headers are present (the programs is complied without any warnings). Thank you in advance and Best wishes, Kirill ||

2 4

[release] Boost 1.77.0 Release Candidate 1
by Marshall Clow 06 Aug '21

06 Aug '21

The first release candidates for the 1.77.0 release are now available at: <https://boostorg.jfrog.io/artifactory/main/release/1.77.0/source/> The SHA256 checksums are as follows: fc9f85fc030e233142908241af7a846e60630aa7388de9a5fafb1f3a26840854 boost_1_77_0_rc1.tar.bz2 f2dd9722b21450daf5ce8ef82c2d99c7ec304f913ee6c6b7f047d5639503dda1 boost_1_77_0_rc1.7z 5347464af5b14ac54bb945dc68f1dd7c56f0dad7262816b956138fc53bcc0131 boost_1_77_0_rc1.tar.gz d2886ceff60c35fc6dc9120e8faa960c1e9535f2d7ce447469eae9836110ea77 boost_1_77_0_rc1.zip As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release managers

4 4

Boost multiprecision as array index
by Claudio La Rosa 03 Aug '21

03 Aug '21

Hi to all, I unsuccessfully tried to use a boost multiprecision variable (object?) as index of an array. Int myArray[100]; uint128_t index = 23; int value = myArray[index]; This code don’t work. There is a way for to use a multiprecision as index of an array? Thanks. Claudio La Rosa

2 3

[Boost.Json] Loss of precision during serialization/parsing plain double ?
by Marc Viala 03 Aug '21

03 Aug '21

Hello Boost users, I'm starting to implement some serialization tools with Boost.Json but I've got some precision issues with double values. To demonstrate this "potential" issue, you will find here after a code snippet to reproduce it: #include <boost/json.hpp> BOOST_AUTO_TEST_CASE(bjson_double_serialize_ut) { namespace bjs = boost::json; static double ref_values[] = { 1217.2772861138403 , -161.68713249779881 , 267.04251495962637}; std::string s; { const bjs::value jv = { ref_values[0] , ref_values[1], ref_values[2], 0.0, 0.0, 0.0}; s = serialize(jv); } double values[3] = {}; { const auto jv{bjs::parse(s)}; values[0] = jv.as_array().at(0).as_double(); values[1] = jv.as_array().at(1).as_double(); values[2] = jv.as_array().at(2).as_double(); } static constexpr auto eps{std::numeric_limits<double>::epsilon()}; BOOST_TEST(std::abs(ref_values[0] - values[0]) <= eps); BOOST_TEST(std::abs(ref_values[1] - values[1]) <= eps); BOOST_TEST(std::abs(ref_values[2] - values[2]) <= eps); } When I compiling and running this code w/ Boost 1.75 and Microsoft Visual C++ version 14.2 (VS 2019) / Windows 10, I've got the following output: "bjson_double_serialize_ut": check std::abs(ref_values[0] - values[0]) <= eps has failed [2.2737367544323206e-13 > 2.2204460492503131e-16] "bjson_double_serialize_ut": check std::abs(ref_values[2] - values[2]) <= eps has failed [5.6843418860808015e-14 > 2.2204460492503131e-16] >From my point of view, I'm expecting to get a tolerance equal or inf. to my "double machine epsilon". Is this correct and how can I address it ? Marc -- Marc Viala

1 0

UUID
by Ming Cheng 30 Jul '21

30 Jul '21

I have a UUID requirement as: * Each session will also be represented with a Universally Unique ID (UUID), which should be a current timestamp * a unique UUID value set by the customer as a 64-bit value. CME Group recommends using the system timestamp which represents the number of microseconds since epoch (Jan 1, 1970) as the timestamp. * I also need to save it in a Linux file and rebuild the UUID from the saved value. Wondering whether boost UUID code can support it? I checked online document and seems to me quite difficulty except archiving.

5 11

g++ linking error with lboost_program_options
by Stefano Gragnani 27 Jul '21

27 Jul '21

The development system is: MacBook Pro Intel i9 MacOS Big Sur 11.4 gcc version 11.1.0 (Homebrew GCC 11.1.0_1) clang version 12.0.0 I'm having trouble compiling some examples from the book 'Boost C ++ Application Development Cookbook’. The problem occurs only with g ++, with clang there is no error. Mistakes only occur when linking to -lboost_program_options, -lboost_system and -lboost_filesystem, with any other library (eg -lboost_chrono) everything is fine. Furthermore, it should be noted that by linking with -lboost_system and -lboost_filesystem no compilation / linking errors are obtained but we get a SEGMENTATION FAULT (ONLY when compiling with g++, compiling with Clang the program run fine), instead linking with -lboost_program_options results in linking errors. This is the example: #include <boost/program_options.hpp> #include <iostream> namespace opt = boost::program_options; int main(int argc, char *argv[]) { // Constructing an options describing variable and giving it a // textual description "All options" opt::options_description desc("All options"); // When we are adding options, first parameter is a name // to be used in command line. Second parameter is a type // of that option, wrapped in value<> class. Third parameter // must be a short description of that option. desc.add_options() ("apples", opt::value<int>(), "how many apples do you have") ("oranges", opt::value<int>(), "how many oranges do you have") ("help", "produce help message") ; // Variable to store our command line arguments opt::variables_map vm; // Parsing and storing arguments opt::store(opt::parse_command_line(argc, argv, desc), vm); // Must be called after all the parsing and storing opt::notify(vm); if (vm.count("help")) { std::cout << desc << "\n"; return 1; } std::cout << "Fruits count: " << vm["apples"].as<int>() + vm["oranges"].as<int>() << std::endl; } and these are the errors: Undefined symbols for architecture x86_64: "__ZN5boost15program_options11to_internalERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", referenced from: __ZN5boost15program_options11to_internalINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEESt6vectorIS7_SaIS7_EERKS8_IT_SaISB_EE in ccmlvHtI.o "__ZN5boost15program_options16validation_error12get_templateB5cxx11ENS1_6kind_tE", referenced from: __ZN5boost15program_options16validation_errorC1ENS1_6kind_tERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESA_i in ccmlvHtI.o "__ZN5boost15program_options19options_descriptionC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEjj", referenced from: _main in ccmlvHtI.o "__ZN5boost15program_options20invalid_option_valueC1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", referenced from: __ZN5boost15program_options8validateIicEEvRNS_3anyERKSt6vectorINSt7__cxx1112basic_stringIT0_St11char_traitsIS7_ESaIS7_EEESaISB_EEPT_l in ccmlvHtI.o "__ZN5boost15program_options22error_with_option_nameC2ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES9_S9_i", referenced from: __ZN5boost15program_options16validation_errorC1ENS1_6kind_tERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESA_i in ccmlvHtI.o "__ZN5boost15program_options3argB5cxx11E", referenced from: __ZNK5boost15program_options11typed_valueIicE4nameB5cxx11Ev in ccmlvHtI.o "__ZN5boost15program_options6detail7cmdline21set_additional_parserENS_9function1ISt4pairINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESA_ERKSA_EE", referenced from: __ZN5boost15program_options25basic_command_line_parserIcE12extra_parserENS_9function1ISt4pairINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESA_ERKSA_EE in ccmlvHtI.o "__ZN5boost15program_options6detail7cmdlineC2ERKSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS9_EE", referenced from: __ZN5boost15program_options25basic_command_line_parserIcEC1EiPKPKc in ccmlvHtI.o "__ZN5boost15program_optionslsERSoRKNS0_19options_descriptionE", referenced from: _main in ccmlvHtI.o "__ZNK5boost15program_options22abstract_variables_mapixERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", referenced from: __ZNK5boost15program_options13variables_mapixERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE in ccmlvHtI.o "__ZNK5boost15program_options22error_with_option_name23substitute_placeholdersERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", referenced from: __ZTVN5boost15program_options20invalid_option_valueE in ccmlvHtI.o __ZTVN5boost15program_options16validation_errorE in ccmlvHtI.o __ZTVN5boost10wrapexceptINS_15program_options16validation_errorEEE in ccmlvHtI.o __ZTVN5boost10wrapexceptINS_15program_options20invalid_option_valueEEE in ccmlvHtI.o "__ZNK5boost15program_options29value_semantic_codecvt_helperIcE5parseERNS_3anyERKSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaISB_EEb", referenced from: __ZTVN5boost15program_options11typed_valueIicEE in ccmlvHtI.o ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status The terminal process "zsh '-c', 'g++-11 -g -I/usr/local/Cellar/boost/1.76.0/include/ -I/usr/local/include/ -L/usr/local/Cellar/boost/1.76.0/lib/ -lboost_program_options -std=gnu++20 Chapter01/01_A_program_options_base/main.cpp -o Chapter01/01_A_program_options_base/main'" terminated with exit code: 1. The compile options are (Visual Studio Code): "label": "Build with g++ 11", "type": "shell", "command": "g++-11", "args": [ "-g", "-I/usr/local/Cellar/boost/1.76.0/include/", "-I/usr/local/include/", "-L/usr/local/Cellar/boost/1.76.0/lib/", "-lboost_program_options", // "-lboost_system", // "-lboost_filesystem", // "-lboost_chrono", "-std=gnu++20", "Chapter01/01_A_program_options_base/main.cpp", // "-L/usr/local/Cellar/gcc/11.1.0_1/lib/gcc/11/", "-o", "Chapter01/01_A_program_options_base/main" ] Thanks Stefano Gragnani

3 5

g++ linking error with lboost_program_options
by Stefano Gragnani 23 Jul '21

23 Jul '21

I have the same problem with boost.regex: Clang compiles correctly and g ++ gives linking errors

1 0

Trouble compiling with float128 data type
by Stefano Gragnani 22 Jul '21

22 Jul '21

Hi, I'm having trouble compiling code that contains float128 data type. I'm using MacOS Big Sur 11.4. Compiler: gcc version 11.1.0 (Homebrew GCC 11.1.0_1) I have no other problems with Boost, the only problem is when I use float128. Please note that I have no problem compiling using libquadmath without using Boost using the __float128 data type. I use Visual Studio Code: "tasks": [ { "label": "Build with g++ 11", "type": "shell", "command": "g++-11", "args": [ "-g", "-I/usr/local/Cellar/boost/1.76.0/include/", "-I/usr/local/include/", "-L/usr/local/Cellar/boost/1.76.0/lib/", "-L/usr/local/Cellar/gcc/11.1.0_1/lib/gcc/11/", "-L/usr/local/Cellar/gmp/6.2.1/lib/", "-L/usr/local/Cellar/mpfr/4.1.0/lib/", "-lmpfr", "-lgmp", "-lquadmath", "-lboost_system", "-lboost_filesystem", "-std=c++20", "'-fext-numeric-literals'", "float128_example.cpp", "-o", "main" ], "group": { "kind": "build", "isDefault": true } }, There are other libraries (gmp, mpfr, ...) because I have compiled several examples taken from the Boost site (such as, for example, automatic_differentation.cpp, GMP_example.cpp, MPFR_example.cpp etc.) and they all compile and run correctly. I tried to compile the following example: #include <boost/cstdfloat.hpp> // For float_64_t, float128_t. Must be first include! //#include <boost/config.hpp> #include <boost/multiprecision/float128.hpp> #include <boost/math/special_functions.hpp> // For gamma function. #include <boost/math/constants/constants.hpp> // For constants pi, e ... #include <typeinfo> // #include <cmath> // for pow function. int main() { try { //[float128_example_3 // Always use try'n'catch blocks to ensure any error messages are displayed. //`Ensure that all possibly significant digits (17) including trailing zeros are shown. std::cout.precision(std::numeric_limits<boost::float64_t>::max_digits10); std::cout.setf(std::ios::showpoint); // Show all significant trailing zeros. //] [/ float128_example_3] #ifdef BOOST_FLOAT128_C std::cout << "Floating-point type boost::float128_t is available." << std::endl; std::cout << " std::numeric_limits<boost::float128_t>::digits10 == " << std::numeric_limits<boost::float128_t>::digits10 << std::endl; std::cout << " std::numeric_limits<boost::float128_t>::max_digits10 == " << std::numeric_limits<boost::float128_t>::max_digits10 << std::endl; #else std::cout << "Floating-point type boost::float128_t is NOT available." << std::endl; #endif show_versions(""); using boost::multiprecision::float128; // Wraps, for example, __float128 or _Quad. // or //using namespace boost::multiprecision; std::cout.precision(std::numeric_limits<float128>::max_digits10); // Show all potentially meaningful digits. std::cout.setf(std::ios::showpoint); // Show all significant trailing zeros. // float128 pi0 = boost::math::constants::pi(); // Compile fails - need to specify a type for the constant! float128 pi1 = boost::math::constants::pi<float128>(); // Returns a constant of type float128. std::cout << sqrt(pi1) << std::endl; // 1.77245385090551602729816748334114514 float128 pi2 = boost::math::constants::pi<__float128>(); // Constant of type __float128 gets converted to float128 on the assignment. std::cout << sqrt(pi2) << std::endl; // 1.77245385090551602729816748334114514 // DIY decimal digit literal constant, with suffix Q. float128 pi3 = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348Q; std::cout << sqrt(pi3) << std::endl; // 1.77245385090551602729816748334114514 // Compare to ready-rolled sqrt(pi) constant from Boost.Math: std::cout << boost::math::constants::root_pi<float128>() << std::endl; // 1.77245385090551602729816748334114514 // DIY decimal digit literal constant, without suffix Q, suffering seventeen silent digits loss of precision! float128 pi4 = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348; std::cout << sqrt(pi4) << std::endl; // 1.77245385090551599275151910313924857 … … what i get is: > Executing task: g++-11 -g -I/usr/local/Cellar/boost/1.76.0/include/ -I/usr/local/include/ -L/usr/local/Cellar/boost/1.76.0/lib/ -L/usr/local/Cellar/gcc/11.1.0_1/lib/gcc/11/ -L/usr/local/Cellar/gmp/6.2.1/lib/ -L/usr/local/Cellar/mpfr/4.1.0/lib/ -lmpfr -lgmp -lquadmath -lboost_system -lboost_filesystem -std=c++20 '-fext-numeric-literals' float128_example.cpp -o main < float128_example.cpp: In function 'int main()': float128_example.cpp:143:56: error: conversion from 'boost::math::constants::detail::constant_return<__float128, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >::type' {aka '__float128'} to non-scalar type 'boost::multiprecision::float128' {aka 'boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>'} requested 143 | float128 pi2 = boost::math::constants::pi<__float128>(); // Constant of type __float128 gets converted to float128 on the assignment. | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ float128_example.cpp:147:18: error: conversion from '__float128' to non-scalar type 'boost::multiprecision::float128' {aka 'boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>'} requested 147 | float128 pi3 = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348Q; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ float128_example.cpp:160:37: error: conversion from '__float128' to non-scalar type 'const float128' {aka 'const boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>'} requested 160 | constexpr float128 pi_constexpr = 3.1415926535897932384626433832795028841971693993751058Q; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/local/Cellar/boost/1.76.0/include/boost/math/special_functions/gamma.hpp:23, from /usr/local/Cellar/boost/1.76.0/include/boost/math/special_functions/detail/bessel_jy.hpp:14, from /usr/local/Cellar/boost/1.76.0/include/boost/math/special_functions/bessel.hpp:20, from /usr/local/Cellar/boost/1.76.0/include/boost/math/special_functions/airy.hpp:12, from /usr/local/Cellar/boost/1.76.0/include/boost/math/special_functions.hpp:15, from float128_example.cpp:22: float128_example.cpp:172:83: in 'constexpr' expansion of 'boost::math::constants::root_pi<boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off> >()' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:237:54: error: 'constexpr typename boost::math::constants::detail::constant_return<Real, Policy>::type boost::math::constants::root_pi() [with T = boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>; Policy = boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>; typename boost::math::constants::detail::constant_return<Real, Policy>::type = const boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>&]' called in a constant expression 237 | { return name<T, boost::math::policies::policy<> >(); }\ | ^ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:269:3: note: in expansion of macro 'BOOST_DEFINE_MATH_CONSTANT' 269 | BOOST_DEFINE_MATH_CONSTANT(root_pi, 1.772453850905516027298167483341145182e+00, "1.77245385090551602729816748334114518279754945612238712821380778985291128459103218137495065673854466541622682362e+00") | ^~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:269:30: note: 'constexpr typename boost::math::constants::detail::constant_return<Real, Policy>::type boost::math::constants::root_pi() [with T = boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>; Policy = boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>; typename boost::math::constants::detail::constant_return<Real, Policy>::type = const boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>&]' is not usable as a 'constexpr' function because: 269 | BOOST_DEFINE_MATH_CONSTANT(root_pi, 1.772453850905516027298167483341145182e+00, "1.77245385090551602729816748334114518279754945612238712821380778985291128459103218137495065673854466541622682362e+00") | ^~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:234:116: note: in definition of macro 'BOOST_DEFINE_MATH_CONSTANT' 234 | template <typename T, typename Policy> inline BOOST_CONSTEXPR typename detail::constant_return<T, Policy>::type name(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(T) BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(Policy)) BOOST_MATH_NOEXCEPT(T)\ | ^~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:235:57: error: call to non-'constexpr' function 'static const T& boost::math::constants::detail::constant_root_pi<T>::get(const std::integral_constant<int, 4>&) [with T = boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>]' 235 | { return detail:: BOOST_JOIN(constant_, name)<T>::get(typename construction_traits<T, Policy>::type()); }\ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:269:3: note: in expansion of macro 'BOOST_DEFINE_MATH_CONSTANT' 269 | BOOST_DEFINE_MATH_CONSTANT(root_pi, 1.772453850905516027298167483341145182e+00, "1.77245385090551602729816748334114518279754945612238712821380778985291128459103218137495065673854466541622682362e+00") | ^~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:207:27: note: 'static const T& boost::math::constants::detail::constant_root_pi<T>::get(const std::integral_constant<int, 4>&) [with T = boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>]' declared here 207 | static inline const T& get(const std::integral_constant<int, construct_from_string>&)\ | ^~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:207:27: note: in definition of macro 'BOOST_DEFINE_MATH_CONSTANT' 207 | static inline const T& get(const std::integral_constant<int, construct_from_string>&)\ | ^~~ float128_example.cpp:186:20: error: call of overloaded 'exp(__float128)' is ambiguous 186 | float128 e1 = exp(1.Q); // Note argument to exp is type float128. | ~~~^~~~~ In file included from /usr/local/Cellar/gcc/11.1.0_1/include/c++/11.1.0/cmath:45, from /usr/local/Cellar/boost/1.76.0/include/boost/config/no_tr1/cmath.hpp:21, from /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/config.hpp:19, from /usr/local/Cellar/boost/1.76.0/include/boost/math/cstdfloat/cstdfloat_types.hpp:18, from /usr/local/Cellar/boost/1.76.0/include/boost/cstdfloat.hpp:18, from float128_example.cpp:19: /usr/local/Cellar/gcc/11.1.0_1/lib/gcc/11/gcc/x86_64-apple-darwin20/11.1.0/include-fixed/math.h:376:15: note: candidate: 'double exp(double)' 376 | extern double exp(double); | ^~~ In file included from /usr/local/Cellar/boost/1.76.0/include/boost/config/no_tr1/cmath.hpp:21, from /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/config.hpp:19, from /usr/local/Cellar/boost/1.76.0/include/boost/math/cstdfloat/cstdfloat_types.hpp:18, from /usr/local/Cellar/boost/1.76.0/include/boost/cstdfloat.hpp:18, from float128_example.cpp:19: /usr/local/Cellar/gcc/11.1.0_1/include/c++/11.1.0/cmath:226:3: note: candidate: 'constexpr long double std::exp(long double)' 226 | exp(long double __x) | ^~~ /usr/local/Cellar/gcc/11.1.0_1/include/c++/11.1.0/cmath:222:3: note: candidate: 'constexpr float std::exp(float)' 222 | exp(float __x) | ^~~ In file included from /usr/local/Cellar/boost/1.76.0/include/boost/math/cstdfloat/cstdfloat_types.hpp:17, from /usr/local/Cellar/boost/1.76.0/include/boost/cstdfloat.hpp:18, from float128_example.cpp:19: /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/precision.hpp: In instantiation of 'constexpr int boost::math::tools::digits() [with T = __float128]': /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'static const T& boost::math::constants::detail::constant_pi<T>::get_from_variable_precision() [with T = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'static T boost::math::constants::detail::constant_pi<T>::get(const std::integral_constant<int, 0>&) [with T = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'constexpr typename boost::math::constants::detail::constant_return<Real, Policy>::type boost::math::constants::pi() [with T = __float128; Policy = boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>; typename boost::math::constants::detail::constant_return<Real, Policy>::type = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'constexpr typename boost::math::constants::detail::constant_return<T>::type boost::math::constants::pi() [with T = __float128; typename boost::math::constants::detail::constant_return<T>::type = __float128]' float128_example.cpp:143:56: required from here /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/precision.hpp:44:51: error: static assertion failed: ::std::numeric_limits<T>::is_specialized 44 | BOOST_STATIC_ASSERT( ::std::numeric_limits<T>::is_specialized); | ^~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:70:55: note: in definition of macro 'BOOST_STATIC_ASSERT' 70 | # define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__) | ^~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/precision.hpp:44:51: note: 'std::__numeric_limits_base::is_specialized' evaluates to false 44 | BOOST_STATIC_ASSERT( ::std::numeric_limits<T>::is_specialized); | ^~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:70:55: note: in definition of macro 'BOOST_STATIC_ASSERT' 70 | # define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__) | ^~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/precision.hpp:45:62: error: static assertion failed: ::std::numeric_limits<T>::radix == 2 || ::std::numeric_limits<T>::radix == 10 45 | BOOST_STATIC_ASSERT( ::std::numeric_limits<T>::radix == 2 || ::std::numeric_limits<T>::radix == 10); | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:70:55: note: in definition of macro 'BOOST_STATIC_ASSERT' 70 | # define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__) | ^~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/precision.hpp:45:62: note: '((((int)std::__numeric_limits_base::radix) == 2) || (((int)std::__numeric_limits_base::radix) == 10))' evaluates to false 45 | BOOST_STATIC_ASSERT( ::std::numeric_limits<T>::radix == 2 || ::std::numeric_limits<T>::radix == 10); | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:70:55: note: in definition of macro 'BOOST_STATIC_ASSERT' 70 | # define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__) | ^~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp: In instantiation of 'struct boost::detail::deduce_target_char_impl<boost::detail::deduce_character_type_later<__float128> >': /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp:270:89: required from 'struct boost::detail::deduce_target_char<__float128>' /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp:407:92: required from 'struct boost::detail::lexical_cast_stream_traits<const char*, __float128>' /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp:468:15: required from 'struct boost::detail::lexical_converter_impl<__float128, const char*>' /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/try_lexical_convert.hpp:201:44: required from 'bool boost::conversion::detail::try_lexical_convert(const Source&, Target&) [with Target = __float128; Source = const char*]' /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast.hpp:41:60: [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ] /usr/local/Cellar/boost/1.76.0/include/boost/math/tools/convert_from_string.hpp:43:39: required from 'constexpr typename boost::math::tools::convert_from_string_result<T>::type boost::math::tools::convert_from_string(const char*) [with Real = __float128; typename boost::math::tools::convert_from_string_result<T>::type = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'static const T& boost::math::constants::detail::constant_pi<T>::get_from_variable_precision() [with T = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'static T boost::math::constants::detail::constant_pi<T>::get(const std::integral_constant<int, 0>&) [with T = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'constexpr typename boost::math::constants::detail::constant_return<Real, Policy>::type boost::math::constants::pi() [with T = __float128; Policy = boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>; typename boost::math::constants::detail::constant_return<Real, Policy>::type = __float128]' /usr/local/Cellar/boost/1.76.0/include/boost/math/constants/constants.hpp:259:3: required from 'constexpr typename boost::math::constants::detail::constant_return<T>::type boost::math::constants::pi() [with T = __float128; typename boost::math::constants::detail::constant_return<T>::type = __float128]' float128_example.cpp:143:56: required from here /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp:243:54: error: static assertion failed: Target type is neither std::istream`able nor std::wistream`able 243 | BOOST_STATIC_ASSERT_MSG((result_t::value || boost::has_right_shift<std::basic_istream<wchar_t>, T >::value), | ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:31:59: note: in definition of macro 'BOOST_STATIC_ASSERT_MSG' 31 | # define BOOST_STATIC_ASSERT_MSG( ... ) static_assert(__VA_ARGS__) | ^~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/lexical_cast/detail/converter_lexical.hpp:243:54: note: '(((bool)boost::integral_constant<bool, false>::value) || ((bool)boost::integral_constant<bool, false>::value))' evaluates to false 243 | BOOST_STATIC_ASSERT_MSG((result_t::value || boost::has_right_shift<std::basic_istream<wchar_t>, T >::value), | ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/boost/1.76.0/include/boost/static_assert.hpp:31:59: note: in definition of macro 'BOOST_STATIC_ASSERT_MSG' 31 | # define BOOST_STATIC_ASSERT_MSG( ... ) static_assert(__VA_ARGS__) | ^~~~~~~~~~~ The terminal process "zsh '-c', 'g++-11 -g -I/usr/local/Cellar/boost/1.76.0/include/ -I/usr/local/include/ -L/usr/local/Cellar/boost/1.76.0/lib/ -L/usr/local/Cellar/gcc/11.1.0_1/lib/gcc/11/ -L/usr/local/Cellar/gmp/6.2.1/lib/ -L/usr/local/Cellar/mpfr/4.1.0/lib/ -lmpfr -lgmp -lquadmath -lboost_system -lboost_filesystem -std=c++20 '-fext-numeric-literals' float128_example.cpp -o main'" terminated with exit code: 1. Terminal will be reused by tasks, press any key to close it. Thanks Stefano Gragnani Inviato da iPad

2 9

[release] Boost 1.77.0 beta 1 released
by Marshall Clow 14 Jul '21

14 Jul '21

Boost release 1.77.0 beta 1 is now available at: <https://boostorg.jfrog.io/artifactory/main/beta/1.77.0.beta1/source/> The SHA256 checksums are as follows: 1aba2bf9416d71026c9e6bbd10a2b7cfb31b0950baa7ad0861dfb74984d96bd9 boost_1_77_0_b1.zip 55126d149664541ffc9fd1f41b2ec67146d69bdab92e41da4bb8610b755ca9ec boost_1_77_0_b1.7z 1aabe7704e91f4f8d97b81d03ddc21c3396f4b72fc4041f01bfcfc128bac0d73 boost_1_77_0_b1.tar.gz 3d5801790c96d2bc9ed23372c4f9fd963bc2f39fe540e35d7b4fe586ba77dfa7 boost_1_77_0_b1.tar.bz2 For details of what's in the release, see <https://www.boost.org/users/history/version_1_77_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

1 0

geometry: knn search of point to many linestrings?
by Jens Thiele 14 Jul '21

14 Jul '21

Hi, I have lots of linestrings and want to find the k nearest linestrings to some point. Looking at the example /libs/geometry/doc/index/src/examples/rtree/polygons_shared_ptr.cpp I first thought this should be close to the solution and I just could replace the polygons with linestrings. But now I think the nearest query in that example only finds the nearest polygon bounding boxes and not the nearest polygons. Am I correct? If yes, how would one extend that example to find the nearest polygons? Greetings Jens

2 11

[Serialization] Xml serialization extremely slow after upgrade to boost 1.74
by Elizabeta Petreska 14 Jul '21

14 Jul '21

Hi I upgraded my project to use boost 1.74 instead of boost 1.49. After the upgrade serialization time for my project archive is extremely slow. With boost 1.49 my project archive was serialized about 1 to 2 minutes. With boost 1.74 it takes more than 50 minutes (I stopped the process so I do not know the exact time it takes) to do the serialization. I am experiencing this only when doing xml serialization. Binary serialization is good, maybe just one second difference between 1.49 and 1.74. What could be the problem with xml serialization ? Repeatedly stopping and playing the debugger gets me into this function in the call stack: save_start i.e in save(*) where it saves the name of the attribute in the xml archive. and then in save_iterator. basic_xml_oarchive<Archive>::save_start(const char *name) { if(NULL == name) return; // be sure name has no invalid characters std::for_each(name, name + std::strlen(name), detail::XML_name<const char>()); end_preamble(); if(depth > 0){ this->This()->put('\n'); indent(); } ++depth; this->This()->put('<'); this->This()->save(name); (*) pending_preamble = true; indent_next = false; } And then save(name) calls this function template<class InputIterator> void save_iterator(std::wostream &os, InputIterator begin, InputIterator end){ typedef iterators::wchar_from_mb< iterators::xml_escape<InputIterator> > xmbtows; std::copy( xmbtows(begin), xmbtows(end), boost::archive::iterators::ostream_iterator<wchar_t>(os) ); }

1 0

[Boost.Python] Making Python classes and functions available to C++
by Sean Farrow 13 Jul '21

13 Jul '21

Hi all, What is the easiest way of making Python classes and functions available to external C++ applications. The Boost.Python documentation seems to show making C++ classes available to Python, but I can't find anything that shows going the other way. Any help appreciated. Kind regards Sean.

1 0

assembler error while using boost_geometry on HPUX IA64
by Ananta Swain 13 Jul '21

13 Jul '21

Hi Boost Experts, I am using boost geometry headers in our code. While compiling the code on HPUX IA64 with +std=c++11 and +stl=gnu flags, we get a cryptic assembler error. Appreciate any help to understand/debug this error. The testcase: *bash-4.3$ cat geom1.cpp* #include <boost/geometry.hpp> #include <boost/geometry/geometries/linestring.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/multi_linestring.hpp> typedef boost::geometry::model::point<double, 2, boost::geometry::cs::geographic<boost::geometry::degree> > point_t; typedef boost::geometry::model::linestring<point_t > linestring_t; typedef boost::geometry::model::multi_linestring<linestring_t > multilinestring_t; using namespace std; template<typename T, typename S> bool Inside(string one, string two) { T objOne; S objTwo; bool inside = false; boost::geometry::read_wkt(one, objOne); boost::geometry::read_wkt(two, objTwo); inside = boost::geometry::within(objOne, objTwo); return inside; } bool Inside(string wktOne, string wktTwo) { bool inside; inside = Inside<multilinestring_t, linestring_t>(wktOne, wktTwo); return inside; } Compilation command: *bash-4.3$ aCC -c +DD64 +std=c++11 +stl=gnu -I <boost_headers path> geom1.cpp* *ASM_BACKEND fatal error: symbol* `_ZN5boost8geometry6detail7overlay27get_turn_info_linear_linearINS1_6relate5turns13assign_policyILb1EEEE22append_opposite_spikesILNS3_INS6_ILb1EEEE14append_versionE1ENS2_9turn_infoINS0_5model5pointIdLm2ENS0_2cs10geographicINS0_6degreeEEEEENS0_13segment_ratioIdEENS2_21turn_operation_linearINSB_IdLm2ENSD_ISE_EEEENSF_IdEEEENS_5arrayINSG_INSB_IdLm2ENSD_ISE_EEEENSF_IdEEEELm2EEEEENS2_17intersection_infoINS1_9get_turns29unique_sub_range_from_sectionILb0ENS0_7sectionINSA_3boxINSB_IdLm2ENSD_ISE_EEEEEELm2EEENSB_IdLm2ENSD_ISE_EEEENS0_22ever_circling_iteratorIN9__gnu_cxx17__normal_iteratorIPKNSB_IdLm2ENSD_ISE_EEEESt6vectorINSB_IdLm2ENSD_ISE_EEEESaINSB_IdLm2ENSD_ISE_EEEEEEEEEENS0_8strategy12intersection18spherical_segmentsIvEENS1_17no_rescale_policyEEENSK_ILb0ENSL_INSM_INSB_IdLm2ENSD_ISE_EEEEEELm2EEENSB_IdLm2ENSD_ISE_EEEENSN_INSP_ISR_SS_INSB_IdLm2ENSD_ISE_EEEESaINSB_IdLm2ENSD_ISE_EEEEEEEEEENSV_IvEESW_EENSB_IdLm2ENSD_ISE_EEEENSV_IvEESW_EESt20back_insert_iteratorISS_INS9_INSB_IdLm2ENSD_ISE_EEEENSF_IdEENSG_INSB_IdLm2ENSD_ISE_EEEENSF_IdEEEENSH_INSG_INSB_IdLm2ENSD_ISE_EEEENSF_IdEEEELm2EEEEESaINS9_INSB_IdLm2ENSD_ISE_EEEENSF_IdEENSG_INSB_IdLm2ENSD_ISE_EEEENSF_IdEEEENSH_INSG_INSB_IdLm2ENSD_ISE_EEEENSF_IdEEEELm2EEEEEEEEEEbRT0_RKT1_T2_' already defined Thanks, Ananta

1 0

interprocess, how to grow managed_mapped_file when it used to store map<>
by i.nixman＠autistici.org 12 Jul '21

12 Jul '21

hi guys! I want to use boost::interprocess to store some resources (strings) into `bi::map<bi::string, bi::string>` that uses `bi::managed_mapped_file` so I can put the resources in the map once, take the file, and distribute it with the program. the problem is that I cannot calculate the required size in advance, so I want to use `bi::managed_mapped_file::grow ()` before inserting another element into the map. but it doesn't work as i expected, at some point i get exception: what(): boost::interprocess::bad_alloc I know the length of the key string and the length of the value string, how can I find out the size by which I must `grow()` before inserting another element into the map? now my code looks like this: #include <boost/interprocess/managed_mapped_file.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/containers/string.hpp> #include <iostream> int main () { namespace bi = boost::interprocess; using segment_manager_t = bi::managed_mapped_file::segment_manager; using void_allocator = bi::allocator<void, segment_manager_t>; using char_allocator = bi::allocator<char, segment_manager_t>; using char_string = bi::basic_string<char, std::char_traits<char>, char_allocator>; using map_value_type = std::pair<const char_string, char_string>; using map_value_type_allocator = bi::allocator<map_value_type, segment_manager_t>; using map_type = bi::map<char_string, char_string, std::less<char_string>, map_value_type_allocator>; static const char *mapfname = "map.dat"; bi::managed_mapped_file mmfile(bi::open_or_create, mapfname, 1024); { void_allocator alloc_inst(mmfile.get_segment_manager()); map_type *mymap = mmfile.find_or_construct<map_type>("MyMap")(alloc_inst); assert(mymap); for ( int i = 0; i < 100; ++i ) { std::string s = std::to_string(i); char_string key(s.c_str(), alloc_inst); char_string value(s.c_str(), alloc_inst); // bi::managed_mapped_file::grow(mapfname, ???); <<<<<<<<<<<<<<<<<<<<<< mymap->emplace(std::move(key), std::move(value)); } } bi::managed_mapped_file::shrink_to_fit(mapfname); return 0; } (or: https://wandbox.org/permlink/jtTOzlMh16ZS8jG6) any ideas? best!

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[release] Boost 1.77.0 Beta 1 Release Candidate 1 is available
by Marshall Clow 10 Jul '21

10 Jul '21

The first release candidates for the 1.77.0 beta release are now available at: https://boostorg.jfrog.io/artifactory/main/beta/1.77.0.beta1/source/ 1aba2bf9416d71026c9e6bbd10a2b7cfb31b0950baa7ad0861dfb74984d96bd9 boost_1_77_0_b1_rc1.zip 55126d149664541ffc9fd1f41b2ec67146d69bdab92e41da4bb8610b755ca9ec boost_1_77_0_b1_rc1.7z 1aabe7704e91f4f8d97b81d03ddc21c3396f4b72fc4041f01bfcfc128bac0d73 boost_1_77_0_b1_rc1.tar.gz 3d5801790c96d2bc9ed23372c4f9fd963bc2f39fe540e35d7b4fe586ba77dfa7 boost_1_77_0_b1_rc1.tar.bz2 The web site has NOT YET been updated. As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release managers

4 4

Boost on apple silicon
by simsicon 06 Jul '21

06 Jul '21

Hi, I was following the tutorial ( https://www.boost.org/doc/libs/1_76_0/doc/html/boost_asio/tutorial/tuttimer…) on macbook with m1 chip, and try to run the simple code and I meet the following error: Undefined symbols for architecture arm64: "boost::chrono::steady_clock::now()", referenced from: boost::asio::detail::chrono_time_traits<boost::chrono::steady_clock, boost::asio::wait_traits<boost::chrono::steady_clock> >::now() in mock-93ab24.o ld: symbol(s) not found for architecture arm64 clang: error: linker command failed with exit code 1 (use -v to see invocation) I am kind of new to C++ and boost, but I think this issue may be related to apple silicon compatibility? -- Thanks&Best Regards Zhang Zheng

2 1

boost iterator range and filter iterator exception using MSVC
by Olaf Peter 02 Jul '21

02 Jul '21

Hi, using MSVC 2019 in debug mode I get an exception "cannot compare incompatible string_view iterators for equality". Using release mode and Clang/G++ all went fine as expected. - Boost: 1.76 - Visual Studio 2019 16.10.3 in C++17 mode How can it changed to be "portable" for all compiler? What's the reason behind? Using range.data() + size or data.front() + size for e.g. end iterator didn't compile. Thanks in advance! Olaf #include <boost/iterator/filter_iterator.hpp> #include <boost/range/iterator_range.hpp> #include <boost/range/iterator_range_core.hpp> #include <boost/range/iterator_range_io.hpp> #include <string_view> #include <iostream> template <typename RangeType> static auto filter_range(RangeType const& range) { struct separator_predicate { bool operator()(char x) { return '_' != x; } }; // FixMe: MSVC 2019 with '_CONTAINER_DEBUG_LEVEL > 0' triggers // assertion: // "cannot compare incompatible string_view iterators for equality" return boost::make_iterator_range( boost::make_filter_iterator( separator_predicate{}, range.begin(), range.end()), boost::make_filter_iterator( separator_predicate{}, range.end())); } using iterator_type = std::basic_string_view<char>::const_iterator; using string_span = boost::iterator_range<iterator_type>; int main() { // input std::string_view const sv = "Hello_World"; // algorithm get boost::iterator_range, aka string_span auto const range = string_span(sv); // here we are auto const range_f = filter_range(range); std::cout << range_f << '\n'; }

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[nowide] Convert wstring to u8string (C++20)
by Jim Orcheson 01 Jul '21

01 Jul '21

In C++17 and earlier, nowide::narrow can be used to convert from UTF-16 encoded strings (std::wstring) to UTF-8 encoded strings, stored in std::string. C++20 introduced std::u8string for UTF-8 encoded strings and it is incompatible with std::string. Is there some way I can get from std::wstring to std::u8string? It is not at all obvious from the nowide documentation.

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[MP11] Initialize the Nth alternative of an std::variant based on a runtime index
by Dominique Devienne 01 Jul '21

01 Jul '21

Hi. I'm modernizing some code, to use std::variant instead of ad-hoc peudo-variant structs. These structs need to be encoded/decoded via avro::codec_traits specializations, but given that std::variant is variadic, I'm struggling a bit. I've done my research and found peter's [1] and also looked at [2], which I thought might work, but does not, and I don't understand the errors I'm getting with MSVC 2019 in C++17 mode. The code is below, with also a subset of the compiler errors I'm getting. [1] https://www.reddit.com/r/cpp/comments/f8cbzs/creating_stdvariant_based_on_i… [2] https://www.boost.org/doc/libs/develop/libs/mp11/doc/html/mp11.html#mp_with… template <> struct codec_traits<std::monostate> { static void encode(Encoder& e, const std::monostate&) { e.encodeNull(); } static void decode(Decoder& d, std::monostate&) { d.decodeNull(); } }; template <typename... Ts> struct codec_traits<std::variant<Ts...>> { static void encode(Encoder& e, const std::variant<Ts...>& var) { e.encodeUnionIndex(var.index()); std::visit( [&e](const auto& alternative) { avro::encode(e, alternative); }, var ); } static void decode(Decoder& d, std::variant<Ts...>& var) { const size_t index = d.decodeUnionIndex(); if (index >= sizeof...(Ts)) { throw avro::Exception("Invalid Union index"); } auto& alternative = boost::mp11::mp_with_index<sizeof...(Ts)>( index, [&var](auto I) { return var.emplace<I>(); // I is mp_size_t<index>{} here } ) ; avro::decode(d, alternative); } }; 1>Messages.cpp 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70,1): error C2220: the following warning is treated as an error 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70,1): warning C4239: nonstandard extension used: 'initializing': conversion from 'std::monostate' to 'std::monostate &' 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70,1): message : A non-const reference may only be bound to an lvalue 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70): message : while compiling class template member function 'void avro::codec_traits<T>::decode(avro::Decoder &,std::variant<std::monostate,int64_t,double> &)' 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ] 1>D:\pdgm\kits\trunk\Avrocpp\1.9.2-Boost-1.74.0\Win_x64_10_v16_debug\include\avro/Specific.hh(341): message : see reference to function template instantiation 'void avro::codec_traits<T>::decode(avro::Decoder &,std::variant<std::monostate,int64_t,double> &)' being compiled 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ] 1>D:\pdgm\kits\trunk\Avrocpp\1.9.2-Boost-1.74.0\Win_x64_10_v16_debug\include\avro/Specific.hh(333): message : see reference to class template instantiation 'avro::codec_traits<T>' being compiled 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ] 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\codegen/Messages.i.ipp(1527): message : see reference to function template instantiation 'void avro::encode<pdgm::eml::etp12::Datatypes::IndexValue_item_v>(avro::Encoder &,const T &)' being compiled 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ] 1>D:\pdgm\kits\trunk\boost\1.74.0\Win_x64_10_v16_debug\include\boost/mp11/detail/mp_with_index.hpp(87,1): error C2440: 'return': cannot convert from '__int64' to 'std::monostate' 1>D:\pdgm\kits\trunk\boost\1.74.0\Win_x64_10_v16_debug\include\boost/mp11/detail/mp_with_index.hpp(87,1): message : No constructor could take the source type, or constructor overload resolution was ambiguous 1>D:\pdgm\kits\trunk\boost\1.74.0\Win_x64_10_v16_debug\include\boost/mp11/detail/mp_with_index.hpp(371): message : see reference to function template instantiation 'std::monostate boost::mp11::detail::mp_with_index_impl_<3>::call<0,_Ty>(size_t,F &&)' being compiled 1> with 1> [ 1> _Ty=avro::codec_traits<pdgm::eml::etp12::Datatypes::IndexValue_item_v>::decode::<lambda_7e593df011d98e42859c6ecb357b3e3f>, 1> F=avro::codec_traits<pdgm::eml::etp12::Datatypes::IndexValue_item_v>::decode::<lambda_7e593df011d98e42859c6ecb357b3e3f> 1> ] 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70): message : see reference to function template instantiation 'std::monostate boost::mp11::mp_with_index<3,avro::codec_traits<T>::decode::<lambda_7e593df011d98e42859c6ecb357b3e3f>>(size_t,F &&)' being compiled 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v, 1> F=avro::codec_traits<pdgm::eml::etp12::Datatypes::IndexValue_item_v>::decode::<lambda_7e593df011d98e42859c6ecb357b3e3f> 1> ] 1>D:\pdgm\trunk\psc3\SharedComponents\src\lib\pdgm\eml\etp12\Messages.hpp(70): message : while compiling class template member function 'void avro::codec_traits<T>::decode(avro::Decoder &,std::variant<std::monostate,int64_t,double> &)' 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ] 1>D:\pdgm\kits\trunk\Avrocpp\1.9.2-Boost-1.74.0\Win_x64_10_v16_debug\include\avro/Specific.hh(341): message : see reference to function template instantiation 'void avro::codec_traits<T>::decode(avro::Decoder &,std::variant<std::monostate,int64_t,double> &)' being compiled 1> with 1> [ 1> T=pdgm::eml::etp12::Datatypes::IndexValue_item_v 1> ]

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[Asio] boost::system symbols visible despite BOOST_ASIO_DISABLE_VISIBILITY being defined
by Angela Breuer 30 Jun '21

30 Jun '21

Hello, I'm developing a C++11 shared library that uses Boost.Asio (with Boost version 1.72) as a header-only library. Exceptions are disabled as the library is intended to be used on embedded devices that do not support exceptions and, to ensure this is the case, all interfaces in my library have the noexcept operator and I have BOOST_EXCEPTION_DISABLE and BOOST_NO_EXCEPTIONS defined. Additionally, all public interfaces in the library do not expose any Boost / Boost.Asio types. When attempting to hide private symbols in my shared library with the GCC visibility flags and annotations (i.e. -fvisibility=hidden), I learned that I needed to define BOOST_ASIO_DISABLE_VISIBILITY to disable the visibility pragmas in Boost.Asio so the boost::asio symbols will also be hidden. Although I was able to hide the boost::asio symbols with this strategy, this still results in a subset of boost::system symbols being visible. I do have some internal helper free functions that accept a boost::system::error_code. I suspect that they may have something to do with these visible symbols, but they are completely internal to the library and the symbols for those helper functions are not visible when I inspect the library's symbols with nm -DC. I will note that I was able to hide the boost::system symbols by using a linker version script, but I do not wish to maintain an unwieldy list of symbols to export if I can help it. Is there a supported way to hide the boost::system symbols aside from using a linker version script? I have attached nm -DC output along with gcc / g++ invocations for reference. Thank you, -Angela

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MSVC compiler error with boost ver 1.71
by John Emmas 24 Jun '21

24 Jun '21

Hi there - I'm using boost ver 1.71 and I'm seeing a strange problem with VS2019. Simply #including this line at the top of a source file will generate a compiler error if I try to build in Debug mode (Release builds are okay...) #include <boost/property_tree/json_parser.hpp> When I say a "compiler error" I'm not referring to one of the usual CXXXX messages - what happens is this:- >INTERNAL COMPILER ERROR in 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30037\bin\HostX86\x64\CL.exe' > Please choose the Technical Support command on the Visual C++ > Help menu, or open the Technical Support help file for more information >Done building project "ardour.vcxproj" -- FAILED. >========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Just wondering if anyone else has encountered this..? Thanks, John

3 5

Making multiprecision::int saturate
by Emilio Paolini 24 Jun '21

24 Jun '21

Hi everyone, i have the following problem: i need the integer type of boost::multiprecision to saturate, instead of wrapping. Is it possible to change its behaviour? Thanks!

1 0

MPI_ERR_TRUNCATE with Boost.MPI and only blocking communication
by Alex Cumberworth 21 Jun '21

21 Jun '21

I am trying to run some Monte Carlo simulation code I wrote in C++ with MPI via the Boost.MPI wrapper. I use only blocking send and receive calls (i.e. send and recv, never isend or irecv), but after running the program for a few days, I inevitably end up with the following error terminate called after throwing an instance of boost::exception_detail::clone_impl >' what(): MPI_Recv: MPI_ERR_TRUNCATE: message truncated I have seen that this can happen with non-blocking calls are being made, but I cannot see how it can happen with only blocking calls. I am sending and receiving a vector of structs: struct Chain { bool operator==(Chain chain_2); int index; int identity; vector positions; vector orientations; private: friend class boost::serialization::access; template void serialize(Archive& ar, const unsigned int version) { ar& index; ar& identity; ar& positions; ar& orientations; } }; using Chains = vector; where VectorThree is declared elsewhere as class VectorThree { public: VectorThree(int x, int y, int z): m_container {{x, y, z}} {}; VectorThree(): m_container {{0, 0, 0}} {}; VectorThree operator-(); VectorThree operator+(const VectorThree& v_2) const; VectorThree operator-(const VectorThree& v_2) const; bool operator!=(const VectorThree& v_2) const; int& operator[](const size_t& i) { return m_container[i]; }; const int& at(const size_t& i) const { return m_container.at(i); }; VectorThree rotate_half(VectorThree axis); VectorThree rotate(VectorThree origin, VectorThree axis, int turns); VectorThree rotate(VectorThree axis, int turns); int sum(); int abssum(); VectorThree absolute(); VectorThree sort(); private: array m_container; friend class boost::serialization::access; template void serialize(Archive& arch, const unsigned int) { arch& m_container; } }; It sends and receives instances of this object many times before the error occurs. I have narrowed down the calls where the error occurs by printing statements before and after both sending and receiving. The sending code: Chains chains_send {m_us_sim->get_chains()}; cout << "Win " << m_rank << ": Sending chains (size " << chains_send.size() << ") to " << win_i << "\n"; m_world.send(win_i, swap_i, chains_send); cout << "Win " << m_rank << ": Sent chains to " << win_i << "\n"; The receiving code: Chains chains_rec; cout << "Win " << m_rank << ": Recieving chains from " << win_to_win[0] << "\n"; m_world.recv(win_to_win[0], swap_i, chains_rec); cout << "Win " << m_rank << ": Recieved chains (size " << chains_rec.size() << ") from " << win_to_win[0] << "\n"; In the output file before the crash I have Win 0: Recieving chains from 1 Win 1: Sending chains (size 2) to 0 Win 1: Sent chains to 0 I am using version 1.65 of Boost and OpenMPI 2.0.1.

2 1

newbie, Getting Started on Unix Variants
by John 15 Jun '21

15 Jun '21

Please someone help me work through the Getting Started on Unix Variants. I've completed the steps up until 6 Link Your Program to a Boost Library. However, the library shown in the step 6 example, libboost_regex-gcc34-mt-d-1_36.a, doesn't seem to be present in my system. So, it looks like something was not right with the building of this library. What can I do to ensure that the library, libboost_regex-gcc34-mt-d-1_36.a, is made. Thank You, John

1 0

[Serialization] archive_exception from bad interaction serialization() and load_construct_data()
by Boylan, Ross 14 Jun '21

14 Jun '21

In short, combining a class implementation of serialize() with load/save_construct_data as described in the docs writes and reads data twice. Varying the pattern can produce exceptions. My solution is to implement serialize() as a no-op and provide paired load/save_construct_data() functions. Is that actually a solution? Is there a better way? The code at the bottom of this message yields Microsoft C++ exception: boost::archive::archive_exception at memory location 0x000000B8189AC300. When attempting to read in what was just written out. Debugging shows that code attempts to read in the object twice, first in the class-specific load_construct_data function I wrote, and then again in the instance method A::serialize. Since the save operation only wrote it out once, there is nothing, or at least nothing expected, to read and things go badly. The documentation (https://www.boost.org/doc/libs/1_76_0/libs/serialization/doc/serialization.…) says "If there is no such default constructor, the function templates load_construct_data and perhaps save_construct_data will have to be overridden." "perhaps" seems to imply that it is not essential to do so, and since the lack of a default constructor only matters when materializing an object I only wrote a load_construct_data function. The example in the documentation does show both a save_construct_data and a load_construct_data function and if I uncomment save_construct_data in the code below, it runs without error and reconstructs the object. HOWEVER, this only works because the data are written out twice, and then read in twice. I think the problem is that TestBed.exe!boost::archive::detail::pointer_iserializer<boost::archive::text_iarchive,A>::load_object_ptr(boost::archive::detail::basic_iarchive & ar, void * t, const unsigned int file_version) Line 340 at J:\Programs\boost_1_76_0\boost\archive\detail\iserializer.hpp(340) first materializes the object and then--after it is already constructed--passes it off to ar_impl >> boost::serialization::make_nvp(NULL, * static_cast<T *>(t)); at the end, triggering the call to A::serialize and the 2nd read from the archive. For now I have kept the save_construct_data function and made A::serialize a no-op; the serialization framework seem to require that it exist. This appears to work. Boost 1.76 Microsoft Visual Studio Community 2019 v16.10.1 with Language Level /std:c++latest. // TestBed.cpp : This file contains the 'main' function. Program execution begins and ends there. // #include <iostream> #include <fstream> #include <string> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> class A : boost::noncopyable { public: int a1; A(const int x1) : a1(x1) {}; virtual ~A() {}; template<class Archive> void serialize(Archive& ar, const unsigned int version) { ar& a1; }; }; namespace boost { namespace serialization { #if 0 template<class Archive> void save_construct_data(Archive& ar, const A* pa, const unsigned int version) { ar& pa->a1; }; #endif template<class Archive> inline void load_construct_data(Archive& ar, A* pa, const unsigned int file_version) { int x1; ar >> x1; ::new(pa)A(x1); } } } /* these are separate functions partly so RAII will close files*/ void write_out(const std::string& fpath, const A& a) { std::ofstream ofs(fpath); boost::archive::text_oarchive oa(ofs); oa << &a; } A* read_in(const std::string& fpath) { A* pa; std::ifstream ifs(fpath); boost::archive::text_iarchive ia(ifs); ia >> pa; return pa; } int main(int argc, char** argv) { const std::string fname("test.srl"); A a(810); write_out(fname, a); A* aa = read_in(fname); std::cout << "A(" << aa->a1 << std::endl; return 0; }

1 1

[Boost::asio] How to set the name of work_scheduler thread started by boost::asio?
by Marco Guest 09 Jun '21

09 Jun '21

Hello, I'm looking to set custom names to std::threads started indirectly when using boost:asio library (on Linux operating system). I have seen this stack trace for such thread by gdb: pthread_cond_wait () from /lib64/libpthread.so.0 void boost::asio::detail::posix_event::wait<boost::asio::detail::conditionally_enabled_mutex::scoped_lock>(boost::asio::detail::conditionally_enabled_mutex::scoped_lock&) ()2 boost::asio::detail::conditionally_enabled_event::wait(boost::asio::detail::conditionally_enabled_mutex::scoped_lock&) () boost::asio::detail::scheduler::do_run_one(boost::asio::detail::conditionally_enabled_mutex::scoped_lock&, boost::asio::detail::scheduler_thread_info&, boost::system::error_code const&) () boost::asio::detail::scheduler::run(boost::system::error_code&) () boost::asio::detail::resolver_service_base::work_scheduler_runner::operator()() () boost::asio::detail::posix_thread::func<boost::asio::detail::resolver_service_base::work_scheduler_runner>::run() () boost_asio_detail_posix_thread_function () start_thread () from /lib64/libpthread.so.0 clone () from /lib64/libc.so.6 Setting names would be useful to debug my application behaviour in high throughput conditions and to be able to easily check the CPU usage of each thread using “top –H”. Is there a way to do so? Thanks

1 0