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Re: [boost] Potential Boost SAX library
by Bjorn Reese 13 Jan '18

13 Jan '18

On 01/09/18 18:36, Oliver Adams via Boost wrote: > I was wondering if a library I'm developing would be of value to the > Boost community. It is basically an event-driven parsing/serialization > library for common formats using a standard internal representation or > simple pass-through conversions. Would anyone be interested in something > like this being added to Boost? There are two kinds of incremental parsers: push parsers (SAX) and pull parsers (approximately StAX.) Briefly put, push parsers traverses the input automatically and generates events for each token it finds, whereas pull parsers traverses the input manually like an iterator and the current token can be queried. Pull parsers have some significant advantages over push parser: * It is straight-forward to implement a push parser on top of a pull parser. This involves a loop and a switch statement (see [1] for a complete example.) Going in the other direction involves the use of coroutines; most likely stateful coroutines. * Contextual parsing can be done directly, unlike push parsers where you have to maintain contextual state in the event handler. * Push parsers can be used directly in Boost.Serialization archives. * Pull parsers are composable. For instance, you could insert a URL pull parser directly into an HTTP pull parser. For a pull parser framework see: https://github.com/breese/trial.protocol The documentation is a bit old though. [1] http://breese.github.io/trial/protocol/trial_protocol/json/tutorial/push_pa…

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Re: [boost] [system] Would it be possible to trial a breaking change to Boost.System and see what happens?
by Bjorn Reese 13 Jan '18

13 Jan '18

On 01/12/18 18:43, Niall Douglas via Boost wrote: > 2. Success becomes solely the default constructed error code, which is > code zero and a new category of "null_category". This is internally > represented by { 0, nullptr }, and thus makes the default constructor > trivial which is highly desirable as it eliminates any compiler magic > static fencing for the default constructor. Right now the default > constructor uses system_category with value 0, and I suspect no code > will notice this change either. Does this mean that custom error categories have to change their make_error_code(e) function to either return a default constructed error_code in case the error value indicates success, or a custom error_code otherwise? In other words, today we do this: namespace my { std::error_code make_error_code(my::errc e) { return std::error(e, my::category()); } } Should that be changed to this? namespace my { std::error_code make_error_code(my::errc e) { if (e == my::success) return std::error_code(); return std::error_code(e, my::category); } }

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[date_time] building documentation?
by James E. King, III 12 Jan '18

12 Jan '18

I cannot build the documentation for Boot.DateTime on the develop tip - I get an error - am I doing something wrong in the command line or is it just broken? jking@ubuntu:~/boost/libs/date_time/doc$ ../../../b2 boostdoc Performing configuration checks - default address-model : 64-bit - default architecture : x86 ../xmldoc/Jamfile.v2:54: in modules.load *** argument error * rule doxygen ( target : sources + : requirements * : default-build * : usage-requirements * ) * called with: ( date_time_autodoc : : <doxygen:param>ENABLE_PREPROCESSING=NO <xsl:param>boost.doxygen.reftitle=Date Time Reference <doxygen.doxproc.title>Date Time Reference <doxygen.doxproc.id>date_time_reference ) * missing argument sources /home/jking/boost/tools/build/src/tools/doxygen.jam:622:see definition of rule 'doxygen' being called /home/jking/boost/tools/build/src/build/project.jam:325: in load-jamfile /home/jking/boost/tools/build/src/build/project.jam:64: in load /home/jking/boost/tools/build/src/build/project.jam:145: in project.find /home/jking/boost/tools/build/src/build/targets.jam:401: in find-really /home/jking/boost/tools/build/src/build/targets.jam:474: in class(a)project-target.find /home/jking/boost/tools/build/src/build/targets.jam:858: in resolve-reference /home/jking/boost/tools/build/src/build/targets.jam:875: in targets.generate-from-reference /home/jking/boost/tools/build/src/build/targets.jam:1226: in generate-dependencies /home/jking/boost/tools/build/src/build/targets.jam:1280: in class(a)basic-target.generate /home/jking/boost/tools/build/src/build/targets.jam:770: in generate-really /home/jking/boost/tools/build/src/build/targets.jam:742: in class(a)main-target.generate /home/jking/boost/tools/build/src/build-system.jam:796: in load /home/jking/boost/tools/build/src/kernel/modules.jam:295: in import /home/jking/boost/tools/build/src/kernel/bootstrap.jam:139: in boost-build /home/jking/boost/boost-build.jam:17: in module scope

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[date_time] [build] new windows class of build error?
by James E. King, III 12 Jan '18

12 Jan '18

I enabled appveyor for Boost.DateTime pull requests and they are failing miserably when <cxxstd> is specified more than once. I don't remember this occurring in the past. This happens on Visual Studio, cygwin, mingw builds. Is this new Boost.Build behavior? https://ci.appveyor.com/project/jeking3/date-time-1evbf/build/1.0.3-develop error: Name clash for '<pstage\lib>libboost_atomic-vc140-mt-x32-1_67.lib' error: error: Tried to build the target twice, with property sets having error: these incompatible properties: error: error: - <cxxstd>14 error: - <cxxstd>17 error: error: Please make sure to have consistent requirements for these error: properties everywhere in your project, especially for install error: targets. Command exited with code 1

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Informal CMake meeting at CPPCon
by Robert Ramey 12 Jan '18

12 Jan '18

Thursday 28 Sept 8 AM at CPPCon a small group of us met to talk a little regarding the situation regarding support of CMake by Boost. I promoted this meeting as I've been concerned that the only discernible results of the recent Boost Steering Committee announcement on the subject was a certain level of antagonism among boost members regarding the subject. Participants ============ Robert Ramey (me) Rene Rivera Vinnie Falco Louis Dionne David Sankel Matt Calabrese This was a small but I think a representative group. After some preliminary back and forth, I think we agreed: a) Nothing was going change regarding the current build system until there was a real alternative in place. b) That we should support serious proposals to implement CMake support within boost. c) And that any such proposals should go through the Boost formal review process. Traditionally, the boost formal review process has never applied to boost tools so this would be a departure from traditional practice. d) Questions regarding the scope/implemention of such support for CMake can be handled within the formal review process. e) Other questions regarding support CMake and Boost, transition to new system, related requirements on boost libraries, etc. can be better addressed once we have some sort of consensus on the form that CMake support will take. I had contacted Paul Fultz who is the only one I know of that has proposed something specific to submit to formal review. He told me he couldn't do it at the time, but shortly there after posted such a request on the list. So I guess for now we're on our way. My motivation for posting this is to keep the boost community up to date on what's happening so that no one gets overly surprised when things start to happen. I'm not really soliciting feedback - though it wouldn't surprise me if I get some. Robert Ramey

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[scope_exit] (Boost >= 1.65) VS 2015 internal compiler error in lambda
by Tobias Loew 12 Jan '18

12 Jan '18

Hi, starting from Boost version 1.65 and using VS 2015 Update 3 (MSVC 19.00) the following code raises an internal compiler error: fatal error C1001: An internal error has occurred in the compiler. (compiler file 'msc1.cpp', line 1468). With earlier Boost versions it compiles fine. Tobias -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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Issue with bjam and building for NDK
by Robert Dailey 11 Jan '18

11 Jan '18

I filed an issue over at the Android NDK github page here: https://github.com/android-ndk/ndk/issues/616 When I invoke b2 to build boost using the standalone toolchain generated by the NDK, bjam seems to be wrapping the command in quotes, like "clang++". This throws off their logic in the clang++.cmd batch script. I was asked to test running b2 without quotes (e.g. clang++), but I am not sure how to do this. Could someone help me understand if this is a code change to b2? Or if there's a jam script somewhere I can modify? I'm not sure if this is a boost issue or an NDK issue at this point. I appreciate any help from the boost developers.

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[contract] ready to release
by Lorenzo Caminiti 10 Jan '18

10 Jan '18

Hello release managers & all, Boost.Contract in master is ready to be added to the next Boost release (regression tests pass, docs are updated, etc.). What do I have to do to put https://github.com/boostorg/contract.git master into Boost release 1.67? Thank you. --Lorenzo

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Potential Boost SAX library
by Oliver Adams 10 Jan '18

10 Jan '18

Hi all, I was wondering if a library I'm developing would be of value to the Boost community. It is basically an event-driven parsing/serialization library for common formats using a standard internal representation or simple pass-through conversions. Would anyone be interested in something like this being added to Boost? Thanks.

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[outcome] Training video in post-Toronto std::expected<T, E>
by Niall Douglas 09 Jan '18

09 Jan '18

In preparation for the Outcome v2 review next week, reviewers may find the video of my Meeting C++ talk in Berlin last year useful to watch beforehand. The talk is a literature review covering all the WG21 papers related to the post-Toronto std::expected<T, E>, which is quite different to the Expected during the Outcome v1 review. https://www.youtube.com/watch?v=JfMBLx7qE0I My thanks to Jens for prioritising the release of this video, and for running a great C++ conference. I'm still building a list of errata for the video, once complete I'll post a list underneath it. Any mistakes that I made, please do let me know, ideally with a timestamp offset into the video. My thanks to all those who are currently reporting so many, many bugs in the reference docs. I'll try my best to fix them all before end of next week, but keep them coming! Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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