November 2018 - Boost-users - lists.preview.boost.org

boost::units - converting from one derived_dimension to another across systems (imperial to metric)
by Matt Vinson 19 Nov '18

19 Nov '18

I am having trouble converting from one derived_dimension to another across systems (imperial to metric). I'd like to convert, say, lb/in to, say, kg/m. I thought I would do the following but get a compiler error #: *.h-------------------------------------------------------------------------------- namespace dimensional_analysis { namespace lineal_force { //lb/in typedef boost::units::derived_dimension< boost::units::us::pound_force_base_unit, 1, boost::units::us::inch_base_unit, -1 >::type lb_per_inch_dimension; typedef boost::units::unit< lb_per_inch_dimension, dimensional_analysis::lengths::ip_system > lb_per_inch_unit; typedef boost::units::quantity<lb_per_inch_unit, double> lb_per_inch_quantity; BOOST_UNITS_STATIC_CONSTANT(lbpin, lb_per_inch_quantity); //kg/m typedef boost::units::derived_dimension< boost::units::si::kilogram_base_unit, 1, boost::units::si::meter_base_unit, -1 >::type kg_per_meter_dimension; typedef boost::units::unit< kg_per_meter_dimension, boost::units::si::system > kg_per_meter_unit; typedef boost::units::quantity<kg_per_meter_unit, double> kg_per_meter_unit_quantity; BOOST_UNITS_STATIC_CONSTANT(kgpm, kg_per_meter_unit_quantity); }//lineal_force }//dimensional_analysis *.cp ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- //Do I need these? BOOST_UNITS_DEFINE_CONVERSION_FACTOR(dimensional_analysis::lineal_force::kg_per_meter_unit, dimensional_analysis::lineal_force::lb_per_inch_unit, double, 0.0559974); // exact conversion BOOST_UNITS_DEFAULT_CONVERSION(dimensional_analysis::lineal_force::kg_per_meter_unit, dimensional_analysis::lineal_force::lb_per_inch_unit); //This does not compile# const auto conv_factor_try0 = conversion_factor(dimensional_analysis::lineal_force::kg_per_meter_unit::unit_type(), dimensional_analysis::lineal_force::lb_per_inch_unit::unit_type()); # *\boost_1_68_0\boost\units\detail\conversion_impl.hpp(340): error C2672: 'conversion_factor': no matching overloaded function found (compiling source file...*.cpp) Any help is appreciated

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Bad link in https://www.boost.org/community/groups.html page
by Dan Field 19 Nov '18

19 Nov '18

The https://www.boost.org/community/groups.html page discusses various boost mailing lists. In the section discussing the Users mailing list, there's a link to browse Gmain's searchable archive. This link is dead.

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Broken link in Getting Started Page
by David Demelier 19 Nov '18

19 Nov '18

Hello, The link: (an up-to-date list is always available in the Boost.Build documentation). In the getting started page is broken and ends in 404. https://www.boost.org/doc/libs/1_68_0/more/getting_started/windows.html Regards,

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[Variant] Bug assigning similar, but different concrete types during assignment / ctor relay
by Michael Powell 18 Nov '18

18 Nov '18

Hello, I've got a Boost.Variant confusion going on during ctor relay. I have two types participating in the Variant, an Integer type and a Floating Point type. Both are Numeric as a base class. i.e. something like: template<typename T> struct numeric {}; struct integer : numeric<long> {}; struct floating_point : numeric<double> {}; Then: using constant_value = boost::variant<..., floating_point, integer, ...>; Somewhere during the handling, I have a test case in which I have a constant_value{} starting out in life as an integer{}. However, somewhere during handling, variant is misinterpreting integer (which=3) as a floating_point (which=2). This is incorrect, of course. I could force the issue, I suppose and re-set the value to the integer, but I'd like to understand the issue. I think it's a bug in variant, or perhaps a "feature" confusing integer with floating_point along base class numeric lines? Any ideas

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[release] Boost 1.69.0 Beta 1 Release Candidate 3
by Marshall Clow 17 Nov '18

17 Nov '18

[ Ok, I've rebuilt the RC - and it contains only the changes to function and MPL ] The release candidates for the third 1.69.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.69.0.beta1.rc3/source/> The release notes are not yet final. The SHA256 checksums are as follows: ee0ecd7d31f58474c1e0210089c9e66bd878d4d1e7436ac511e359aa4a9d3e86 ./boost_1_69_0_b1_rc3.7z 3e25c46f2171799caabbeb419ba7859fffb62208f3a1c80798713377ab07af0e ./boost_1_69_0_b1_rc3.tar.bz2 71f4b57175058af1b8c320971cf29226e5a652931a679f7e1c086655147ecafb ./boost_1_69_0_b1_rc3.tar.gz ec9ef7d2c9f0d41f560769e67bc7ff207cc999243a7dd6c3f6bcfbdbf0827a7b ./boost_1_69_0_b1_rc3.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 Boost Release Managers

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Re: [Boost-users] [boost] [release] Boost 1.69.0 Beta 1 Release Candidate 2
by Marshall Clow 16 Nov '18

16 Nov '18

On Thu, Nov 15, 2018 at 11:37 AM Robert Ramey via Boost < boost(a)lists.boost.org> wrote: > On 11/14/18 2:50 PM, Marshall Clow via Boost wrote: > > Marshall, > > I would like to merge development of the serialization library into the > master if there is an opportunity to do so. If not, I'll just wait > until after the release. > After the beta release, sure. > I know you've complained about merging w/o permission. I'm not a git > guru but can't you tag the current state and work with that > independently of what anyone subsequently merges. Also there's creating > a branch for the merge. Also the possibility of keeping the release > candidate on your own machine and only pulling what you want to > explictly merge. Just food for thought? > Or you can merge to release locally and not push those changes until later. -- Marshall

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process group object creation fail with version-1.67, 1.68
by dinesh kumar 16 Nov '18

16 Nov '18

Hi Team, I would like to take this to your notice, as the boost process group object creation is failing, in windows with ${SUBJECT} versions. I've tried 1.66, 1.69-b1-canadiate2 both are working fine. #include <boost/process.hpp> #include <iostream> int main() { try { boost::process::group grp; } catch (std::exception &e) { std::cout << e.what(); } return 0; } *Output* SetInformationJobObject() failed: The handle is invalid. Visual studio version is: 15.8.5 -- Regards, Dinesh manojadinesh.blogspot.com

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[release] Boost 1.69.0 Beta 1 Release Candidate 2
by Marshall Clow 16 Nov '18

16 Nov '18

The release candidates for the second 1.69.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.69.0.beta1.rc2/source/> The release notes are not yet final. The SHA256 checksums are as follows: 77827b25121159a4e65cfbdf19713e2d589fce267fd6f08615a453d24753c9d3 ./boost_1_69_0_b1_rc2.7z ea05c6e01c856369afdab1f6c075e06fb0f965ab1c247f753ed5c951a9db4e71 ./boost_1_69_0_b1_rc2.tar.bz2 b393a73cf084be716c40ef346cfacb1c95e7b14637e8385eeeb50774dd0b99ed ./boost_1_69_0_b1_rc2.tar.gz 74c0c0a19a700fee2b4f434bb7df50840642e3c35924e85864b278bd519af062 ./boost_1_69_0_b1_rc2.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 Boost Release Managers

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[Optional] Lazy initialized optional
by Michael Powell 14 Nov '18

14 Nov '18

Hello, I am looking into deriving from boost::optional and adding lazy initialization capability. I can arrange a constructor, or whatever, to inject an appropriate factory method, functional callback, etc, that's no problem. >From the boost::optional perspective, I'd like to override a key method (or methods, hopefully not too many) in order to inject that factory provided value. I'm thinking optional::get? Unless there's a better override for that? Cheers, Michael Powell

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[release] Boost 1.69.0 Beta 1 Release Candidate 1
by Marshall Clow 14 Nov '18

14 Nov '18

The release candidates for the first 1.69.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.69.0.beta.1.rc1/source/> The release notes are not yet available. The updated documentation is not yet available. [ They will be available in a day or two. ] The SHA256 checksums are as follows: db6b346389714647490d6503db881e4178dd8cd498f850999bebf72cacd4c4ed boost_1_69_0_b1_rc1.7z d128c82351becbd37a02b9b4818994d3f66ff8bdbc0a18838206f4c070db97af boost_1_69_0_b1_rc1.tar.bz2 4df6262db53cfd0d0f934cb126f7e48e94872fe4441cbac6bf72a43bfb136a45 boost_1_69_0_b1_rc1.tar.gz e2908e33cc15f92cda06ddde6a3da43b18967a83105355571fc3cf6e75820c7f boost_1_69_0_b1_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 Boost Release Managers

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