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[outcome] Major changes for Boost 1.72 release
by Niall Douglas 10 Oct '19

10 Oct '19

Just as a heads up to those who care, and any pretesting of these changes in advance of the Boost release is welcome. There are two breaking changes: 1. The git submodule mechanism used by standalone Outcome of specifying dependent libraries has been replaced with a cmake superbuild of dependencies mechanism instead. Upon cmake configure, an internal copy of quickcpplib will be git cloned, built and installed into the build directory from where an internal `find_package()` uses it. This breaks the use of the unconfigured Outcome repo as an implementation of Outcome, one must now do one of: 1. Add Outcome as subdirectory to cmake build 2. Use cmake superbuild (i.e. `ExternalProject_Add()`) to build and install Outcome into a local installation. 3. Use one of the single header editions. 2. For standalone Outcome, the current compiler is now checked for whether it will compile code containing C++ Concepts, and if it does, all cmake consumers of Outcome will enable C++ Concepts. Set the cmake variable `CXX_CONCEPTS_FLAGS` to an empty string to prevent auto detection and enabling of C++ Concepts support occurring. There are two new features: - Standalone outcome is now `make install`-able, and cmake `find_package()` can find it. Note that you must separately install and `find_package()` Outcome's dependency, quickcpplib, else `find_package()` of Outcome will fail. - Support for C++ Coroutines has been added. This comes in two parts, firstly there is now an `OUTCOME_CO_TRY()` operation suitable for performing the `TRY` operation from within a C++ Coroutine. Secondly, in the header `outcome/coroutine_support.hpp` there are implementations of `eager<OutcomeType>` and `lazy<OutcomeType>` which let you more naturally and efficiently use `basic_result` or `basic_outcome` from within C++ Coroutines -- specifically, if the result or outcome will construct from an exception pointer, exceptions thrown in the coroutine return an errored or excepted result with the thrown exception instead of throwing the exception through the coroutine machinery (which in current compilers, has a high likelihood of blowing up the program). Both `eager<T>` and `lazy<T>` can accept any `T` as well. Both have been tested and found working on VS2019 and clang 9. More detail can be found at: https://boostorg.github.io/outcome/changelog.html Niall

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Regarding the End of life of Boost version 1.56
by kamallochan Jena 05 Oct '19

05 Oct '19

Hi, In one of our project we are using Boost 1.56 version. And want to upgrade Boost C++ to a version that is not in an end of life state. My queries are: 1> When is the End Of Life of Boost 1.56 version ? 2> What is the latest stable Boost version we can use instead of Boost version 1.56 ? Can someone help on answering those questions. Thank you in advance! Thanks & Regards, Kljena

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boost::geometry: intersection of a point with a linestring
by Giorgino R 04 Oct '19

04 Oct '19

Hi there, Is there any boost functionality to "split" a linestring with an intersecting point? I was expecting that boost::geometry::intersection could return a multi-linestring (of size two) or a vector of linestrings (size two). For example, please see a very simple case below which doesn't compile: point_2d pt(0.5, 0); > linestring_2d ls({ point_2d(0, 0), point_2d(1, 0), point_2d(3, 0), > point_2d(5, 0) }); > std::vector<linestring_2d> inter; > bg::intersection(pt, ls, inter); Is there any way to get inter vector with two linestrings (linestring_2d({point_2d(0, 0), point_2d(0.5, 0) }) and linestring_2d({point_2d(0.5, 0), point_2d(1, 0), point_2d(3, 0), point_2d(5, 0) }) ) or any multi geometry container that will hold the spatial information of two lines connected in this point? Or should I create these two lines myself by working out which points of the linestring are left and right of the intersecting point? Many thanks in advance.

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Assigning to a boost::asio::ssl::context while asynchronous operations are using it
by Martijn Otto 30 Sep '19

30 Sep '19

I cannot find any definitive documentation on whether it's safe to move-assign to an ssl-context while it is used for asynchronous operations, assuming of course the application is single-threaded. In my tests I could not trigger any failures, but that may be pure luck (or not lucky at all depending on point of view).

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catmull_rom returning a single point
by hgrwilson 30 Sep '19

30 Sep '19

Hi all, I am trying to interpolate some data with a *catmull_rom* spline available in boost math (interpolation). However, the resulting spline collapses to a single point for all /s/, corresponding to the first control point, /points_intr[0]/. Below, the c++ code segment of the interpolation is depicted: std::vector<std::array<double, 2>> points_intr(16); points_intr[0] = { 1.263270, 0.774614 }; points_intr[1] = { 1.876, 2.480 }; points_intr[2] = { 1.651110, 4.550 }; points_intr[3] = { 1.426340, 5.688 }; points_intr[4] = { 1.429, 7.054 }; points_intr[5] = { 2.073220, 8.377020 }; points_intr[6] = { 3.910, 9.140 }; points_intr[7] = { 6.430, 9.537 }; points_intr[8] = { 8.950, 9.859 }; points_intr[9] = { 11.470, 10.317 }; points_intr[10] = { 12.730, 10.6456 }; points_intr[11] = { 13.990, 11.0741 }; points_intr[12] = { 15.335, 11.6928 }; points_intr[13] = { 16.680, 12.5661 }; points_intr[14] = { 18.3538, 14.830 }; points_intr[15] = { 18.700, 16.056 }; boost::math::catmull_rom<std::array<double, 2>> interpolator_cr(std::move(points_intr)); auto max_s = interpolator_cr.max_parameter(); std::array<double, 2> inter_points; for (int i = 0; i < 100; i++) { inter_points = interpolator_cr(max_s * (i / num_points)); geometry_msgs::Point p; p.x = inter_points[0]; p.y = inter_points[1]; p.z = z; //p.z = inter_points[2]; marker.points.push_back(p); DEBUG_INFO("spline %d: (x, y) %f, %f, current_s: %f", i, p.x, p.y, max_s * (i / 100.0)); } I'm using boost 1.71.0 -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html

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[Log] using std::shared_ptr and other std primatives rather than the boost counterparts
by Sean Farrow 30 Sep '19

30 Sep '19

Hi, Is is possible ot use std::shared_ptr and other std primatives with boost.log rather than the boost counterparts. I'm converting a codebase from boost namespaces and would like to add logging. Thanks, Sean.

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Re: [Boost-users] <boost/timer/timer.hpp> deprecated ?
by Kenneth Porter 23 Sep '19

23 Sep '19

--On Friday, September 13, 2019 3:35 PM +0100 "avib369 . via Boost-users" <boost-users(a)lists.boost.org> wrote: > How do I get rid of this message ? You could do what it says to do?

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Community blog or tutorial posting for C++
by Matt Zand 22 Sep '19

22 Sep '19

Hi, Does anyone know if there is a way for members to post blogs or tutorials on C++ in the Boost community or website? -- Cheers, Matt Zand Cell: 202-420-9192 Work: 240-200-6131 High School Technology Services <https://myhsts.org/> DC Web Makers <https://dcwebmakers.com/> Coding Bootcamps <https://coding-bootcamps.com/>

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<boost/timer/timer.hpp> deprecated ?
by avib369 . 13 Sep '19

13 Sep '19

How do I get rid of this message ? /tmp/ma0/boost/gcc-7.3/boost_1_71_0/boost/timer.hpp:21:70: note: #pragma message: This header is deprecated. Use the facilities in <boost/timer/timer.hpp> instead. BOOST_HEADER_DEPRECATED( "the facilities in <boost/timer/timer.hpp>" ) Ta, Avi

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boost.asio: win_iocp_serial_port_service::open changes broke FTDI support
by Michael Steinberg 12 Sep '19

12 Sep '19

Hello, the changes to win_iocp_serial_port_service::open in commit c113adc19004770d945672009b3d26f9498099cd broke at least FTDI 4232H but probably all FTDI support for me. SetCommState(handle, &dcb) in new line 99 fails with error code 57. Reverting the commit seems to recover correct behaviour. Kind Regards Michael

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