April 2018 - Boost - lists.preview.boost.org

[release] Boost 1.67.0 Release Candidate 2
by Daniel James 20 Apr '18

20 Apr '18

The second release candidates for the 1.67.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.67.0/source/> The SHA256 checksums are as follows: 1cd94f03a71334a67d36f5161b57f5931e0cd6ecf726d7aca8bd82a3be720b74 boost_1_67_0_rc2.7z 2684c972994ee57fc5632e03bf044746f6eb45d4920c343937a465fd67a5adba boost_1_67_0_rc2.tar.bz2 8aa4e330c870ef50a896634c931adf468b21f8a69b77007e45c444151229f665 boost_1_67_0_rc2.tar.gz 7e37372d8cedd0fd6b7529e9dd67c2cb1c60e6c607aed721f5894d704945a7ec boost_1_67_0_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.

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Bug or change behavior in Fusion at_c in boost 1.66 and 1.67
by Pietro Incardona 18 Apr '18

18 Apr '18

Dear boost developers I used to use boost vector container with arrays like in the code below #include <boost/fusion/sequence/intrinsic/at.hpp> #include <boost/fusion/include/at.hpp> #include <boost/fusion/container/vector.hpp> int main() { boost::fusion::vector<int[3], int, int> v; boost::fusion::at_c<1>(v) = 2; boost::fusion::at_c<0>(v)[0] = 1; //// <----- Broken on newer boost version } Compiled with g++ --std=c++11 -I/home/i-bird/BOOST_166/include -o out main.cpp Unfortunately while this code was working under BOOST 1.63, on Boost 1.66 and Boost 1.67 it does not compile and it produce this error below. It seem that include/boost/fusion/container/vector/detail/value_at_impl.hpp went under some "modernization" process that broke the code above Regards Pietro /////////////////////////// Error ///////////////////////////////////////////// In file included from /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:12:0, from /home/i-bird/BOOST_166/include/boost/fusion/container/vector/vector.hpp:29, from /home/i-bird/BOOST_166/include/boost/fusion/container/vector.hpp:12, from main.cpp:3: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In instantiation of ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: error: no matching function for call to ‘value_at_impl<mpl_::int_<0>::value>(boost::fusion::vector<int [3], int, int>*)’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: candidate: template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: template argument deduction/substitution failed: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘1’ does not match ‘0’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘2’ does not match ‘0’ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In substitution of ‘template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) [with long unsigned int N = 0; U = int [3]]’: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: required from ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: error: function returning an array U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ main.cpp: In function ‘int main()’: main.cpp:9:26: error: no matching function for call to ‘at_c<0>(boost::fusion::vector<int [3], int, int>&)’ boost::fusion::at_c<0>(v)[0] = 1; ^ In file included from main.cpp:1:0: /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: candidate: template<int N, class Sequence> constexpr typename boost::lazy_disable_if<boost::is_const<Sequence>, boost::fusion::result_of::at_c<Sequence, N> >::type boost::fusion::at_c(Sequence&) at_c(Sequence& seq) ^~~~ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: template argument deduction/substitution failed: /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: candidate: template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) at_c(Sequence const& seq) ^~~~ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: substitution of deduced template arguments resulted in errors seen above [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ g++ --std=c++11 -I/home/i-bird/BOOST_167/include -o out main.cpp In file included from /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:12:0, from /home/i-bird/BOOST_167/include/boost/fusion/container/vector/vector.hpp:29, from /home/i-bird/BOOST_167/include/boost/fusion/container/vector.hpp:12, from main.cpp:3: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In instantiation of ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: error: no matching function for call to ‘value_at_impl<mpl_::int_<0>::value>(boost::fusion::vector<int [3], int, int>*)’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: candidate: template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: template argument deduction/substitution failed: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘1’ does not match ‘0’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘2’ does not match ‘0’ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In substitution of ‘template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) [with long unsigned int N = 0; U = int [3]]’: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: required from ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: error: function returning an array U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ main.cpp: In function ‘int main()’: main.cpp:9:26: error: no matching function for call to ‘at_c<0>(boost::fusion::vector<int [3], int, int>&)’ boost::fusion::at_c<0>(v)[0] = 1; ^ In file included from main.cpp:1:0: /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: candidate: template<int N, class Sequence> constexpr typename boost::lazy_disable_if<boost::is_const<Sequence>, boost::fusion::result_of::at_c<Sequence, N> >::type boost::fusion::at_c(Sequence&) at_c(Sequence& seq) ^~~~ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: template argument deduction/substitution failed: /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: candidate: template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) at_c(Sequence const& seq) ^~~~ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: substitution of deduced template arguments resulted in errors seen above

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Proposal of a new container
by Vanand Gasparyan 16 Apr '18

16 Apr '18

Hi everyone, First, a short introduction of me. My name is Vanand, I'm from Armenia, 23 yo, C++ software Engineer. I'm new in the community and I've come with a proposal. I've implemented a prefix tree and tried to make it as STL compatible as possible. After a short investigation I found out that boost libraries don't provide one and here I am with a proposal. Here is the link to the repository: https://github.com/vgasparyan1995/prefix_tree It's a header only implementation, all source files are in "include" directory. I also have unit and performance tests. If the proposal (of having prefix tree container in boost) is accepted, I will ask for mentorship and support to make it "boost friendly" , create a proper documentation, meet the coding style and other guidelines. In the end I want to mention that I am new to this, so if I'm already doing something wrong or this is not the proper way to propose something, please kindly let me know and help to do it right. Looking forward to hearing from anyone :) Best Regards, Vanand

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[release] 1.68.0 open for merging
by Daniel James 15 Apr '18

15 Apr '18

The master branch is open for merging all stable changes from develop, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging does not require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html Release schedule explanation: https://github.com/boostorg/boost/wiki/Release-Schedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Boost Release Team

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[release] Boost 1.67.0
by Daniel James 14 Apr '18

14 Apr '18

Release 1.67.0 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 2 new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <https://www.boost.org/users/news/version_1.67.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.67.0/> To install this release on your system, see <https://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team

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Library for printing STL containers
by Eric Curtin 14 Apr '18

14 Apr '18

Hi Guys, I have tried to contact the developer of this neat little library. It allows you to use streams such as ostringstreams and couts with various STL containers, without the boilerplate of any loops to get all the contents. I will likely fork and maintain it as I have tried (and failed) to contact the developer. https://github.com/louisdx/cxx-prettyprint If I cleaned it up, could we consider it for boost inclusion? It is already under boost open source license.

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MSVC now correctly reports __cplusplus
by degski 12 Apr '18

12 Apr '18

https://blogs.msdn.microsoft.com/vcblog/2018/04/09/msvc-now-correctly-repor… degski

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[release] Boost 1.67.0 Release Candidate 1
by Daniel James 11 Apr '18

11 Apr '18

The release candidates for the 1.67.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.67.0/source/> The SHA256 checksums are as follows: 289d55fc90b637781018c4babe3ba83244175aa539b54bc687529a65e352e713 boost_1_67_0_rc1.7z 0d13e038f8f402ea0d811397876c8e6f2a2352c170f90d0a42bb61dcec3f86fc boost_1_67_0_rc1.tar.bz2 5d25d1cdf6f7061f25463f59ce2e5c9e1cecfece90d86a04513de386c86fbb5e boost_1_67_0_rc1.tar.gz ae8d461a8573d24813c92e3daf1f7832908d1845820d94b77243d6cd06197635 boost_1_67_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.

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[build] Broken doc links
by Gavin Lambert 10 Apr '18

10 Apr '18

Prompted by the thread "Toolset version for Visual Studio 2017 15.6.3" over in the user list, I was looking through some Boost.Build documentation when I found some dead links and other weirdness. Boost.Build's github page links to https://www.boost.org/build/, which appears to be fully working. On https://www.boost.org/doc/libs/1_66_0/more/getting_started/windows.html, under "5.2.1 Install Boost.Build" it links to https://www.boost.org/doc/libs/1_66_0/tools/build/index.html, which appears to be a versioned clone of the above. But at that page, the "Documentation" link points at https://www.boost.org/doc/libs/1_66_0/tools/build/doc/html/index.html, which 404s. Back in "Getting Started", in "5.2.2 Identify Your Toolset" it first links directly to https://www.boost.org/build/doc/html/bbv2/reference/tools.html (which is now an unversioned link, but does work), and then to https://www.boost.org/doc/libs/1_66_0/doc/html/bbv2/installation.html (which is a versioned link that also works). So it's not very consistent. Putting these things together, it looks like the "right" root page for the versioned documentation should be https://www.boost.org/doc/libs/1_66_0/doc/html/bbv2.html, although that lacks some user-friendliness. (And it also links to https://www.boost.org/boost-build2 for yet another URL variation... although that does redirect to https://www.boost.org/build/ at least.)

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please integrate patches for Boost.Gil and Boost.Graph
by Brook Milligan 10 Apr '18

10 Apr '18

I am not sure what the correct procedure for this is, but there are at least two old patches that would improve Boost.Gil and Boost.Graph. I would greatly appreciate it if someone integrates these. I have been using these for some time now with no detrimental effects. The patch to Boost.Gil corrects clearly incorrect code. The patch to Boost.Graph solves a problem that should never have been in the original design in the first place. Since it expands the acceptable set of arguments to cover the full range of values any user would expect and has the original semantics for cases that worked before, as far as I can see there can be no effect on existing user code. Thank you very much. Cheers, Brook See the following: - https://lists.boost.org/Archives/boost/2013/02/200721.php - https://svn.boost.org/trac10/ticket/7270 - https://svn.boost.org/trac10/ticket/9517 - https://svn.boost.org/trac10/attachment/ticket/9517/gil_channel_algorithm.p… - https://svn.boost.org/trac10/ticket/13397 --- boost/gil/channel_algorithm.hpp.orig 2018-02-23 22:45:42.000000000 -0700 +++ boost/gil/channel_algorithm.hpp 2018-03-11 22:05:31.000000000 -0600 @@ -25,6 +25,7 @@ #include "gil_config.hpp" #include "channel.hpp" +#include <limits> #include <boost/mpl/less.hpp> #include <boost/mpl/integral_c.hpp> #include <boost/mpl/greater.hpp> @@ -51,7 +52,7 @@ template <typename UnsignedIntegralChannel> -struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,-1> {}; +struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,std::numeric_limits<UnsignedIntegralChannel>::max()> {}; template <> struct unsigned_integral_max_value<uint8_t> : public mpl::integral_c<uint32_t,0xFF> {}; Allow dimensions to have length >= 1, rather than > 1. See https://svn.boost.org/trac10/ticket/11735. --- boost/graph/grid_graph.hpp.orig 2017-12-13 16:56:43.000000000 -0700 +++ boost/graph/grid_graph.hpp 2018-04-07 09:33:56.000000000 -0600 @@ -630,15 +630,17 @@ // If the vertex is on the edge of this dimension, then its // number of out edges is dependent upon whether the dimension - // wraps or not. - if ((vertex[dimension_index] == 0) || - (vertex[dimension_index] == (length(dimension_index) - 1))) { - out_edge_count += (wrapped(dimension_index) ? 2 : 1); - } - else { - // Next and previous edges, regardless or wrapping - out_edge_count += 2; - } + // wraps or not, but only if the length is > 1. + if (length(dimension_index) > 1) { + if ((vertex[dimension_index] == 0) || + (vertex[dimension_index] == (length(dimension_index) - 1))) { + out_edge_count += (wrapped(dimension_index) ? 2 : 1); + } + else { + // Next and previous edges, regardless or wrapping + out_edge_count += 2; + } + } } return (out_edge_count);

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