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How to build modular boost for android?
by Robert Dailey 19 Jan '15

19 Jan '15

How do I build modular boost for android? I have it checked out from github at the 1.57 tag. I don't see a user-config.jam file, except for at "tools/build/example/user-config.jam". The structure is completely changed, where do I need to make changes? What changes do I make? Any guidance is appreciated. I'm no where near an expert here, I just need a quick ad-hoc solution. Thanks.

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[interval] Guaranteed interval arithmetic for "long double"
by Александров Петр 15 Jan '15

15 Jan '15

Hello. Is guaranteed interval arithmetic for "long double" supported by Boost Interval library on x86-64 CPU, Linux, Clang or GCC? Kind regards, Petr.

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[Coroutine] Migrating coroutines between different threads
by lin li 15 Jan '15

15 Jan '15

Hi, people. I have a question about the coroutines in boost (both the normal Coroutine and the asio couroutine). Can I suspend a coroutine in one thread, then later on resume it in another thread? I have been googling about this and found some (outdated) documents saying that this is not possible ( http://www.crystalclearsoftware.com/soc/coroutine/coroutine/coroutine_threa… ). However, I did not find this warning in the document of the current release. Is this limitation still there or not?

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init log with BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT
by Bill Tian 15 Jan '15

15 Jan '15

Hi guys, I want to define a global logger that can be used in other place. The severity level always be "info". I init the log like this: #include <cstdlib> #include <boost/log/trivial.hpp> #include <boost/log/core.hpp> #include <boost/log/sources/global_logger_storage.hpp> #include <boost/log/sources/severity_logger.hpp> #include <boost/log/sources/record_ostream.hpp> #include <boost/log/sources/severity_feature.hpp> // Here we define our application severity levels. enum severity_level { normal, notification, warning, error, critical }; // The formatting logic for the severity level template< typename CharT, typename TraitsT > inline std::basic_ostream< CharT, TraitsT >& operator<< (std::basic_ostream< CharT, TraitsT >& strm, severity_level lvl) { static const char* const str[] = { "normal", "notification", "warning", "error", "critical" }; if (static_cast<std::size_t>(lvl) < (sizeof(str) / sizeof(*str))) strm << str[lvl]; else strm << static_cast<int>(lvl); return strm; } // Global logger declaration BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(test_lg, boost::log::sources::severity_logger_mt<severity_level>) void try_logging() { boost::log::sources::severity_logger_mt<severity_level>& lg = test_lg::get(); // TODO: // always write "info" record, Unknown reason! BOOST_LOG_SEV(lg, normal) << "This is a normal severity record"; BOOST_LOG_SEV(lg, notification) << "This is a notification severity record"; BOOST_LOG_SEV(lg, warning) << "This is a warning severity record"; BOOST_LOG_SEV(lg, error) << "This is a error severity record"; BOOST_LOG_SEV(lg, critical) << "This is a critical severity record"; } int main(int argc, char* argv[]) { try_logging(); return EXIT_SUCCESS; } In the log i got this: [2015-01-14 19:00:34.800935] [0x40000300] [info] This is a normal severity re cord [2015-01-14 19:00:34.805935] [0x40000300] [info] This is a notification sever ity record [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a warning severity r ecord [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a error severity rec ord [2015-01-14 19:00:34.806935] [0x40000300] [info] This is a critical severity record What do i miss? Thank you! Bill

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Re: [Boost-users] unit test BOOST_CHECK_CLOSE absolute
by lepere renaud 14 Jan '15

14 Jan '15

>> For example, I am comparing coordinates in 2d spaces and the relative >> value is not important, the meaningfull value is the absolute difference >> between coordinates. > > It is almost never true. Related error gives you much better estimate of > closeness. I agree with that most of the time but this is not always true. Just imagine the case you compare lattitude, longitude. In this case, only absolute values make sense. > >> I have seen that I can do a >> BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); >> >> but in this can I don't have a good message when the test fails (it does >> not show the value of x and the expected_x). >> >> In fact I would like to have something like BOOST_CHECK_CLOSE_ABSOLUTE ? >> Is there something equivalent or how can I do something like this ? > > Don't. Specify relative tolerance (or percent tolerance) and keep using > BOOST_CHECK_CLOSE. Relative tolerance will give me false bug report, I want a point to be equal to (0, 0) with a small absolute error and I don't care if it is -1e-15 or +1e-10 so BOOST_CHECK_CLOSE is not an option here and I have to use BOOST_CHECK_SMALL with the absolute difference. The problem with BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); Is that when it fails with the message that does not print the values "x" and "expected_x" and does not say something like x(2.0) is not equal to "expected_x(0.0)" with an difference of 1e-3. I can probably write my own macro combining BOOST_TEST_MESSAGE() and some glues to obtain what I want but I was wondering if someone had the same problem and a solution. Thanks Renaud

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[Boost.build] Building for ARM64
by mefyl 14 Jan '15

14 Jan '15

Hi, In my quest cross-compiling Boost.Context for ARM64, I encounter the following problem (using develop since ARM64 support is not in 1.57): $ ./bootstrap.sh --with-libraries=context [...] $ ./b2 -d2 -q toolset=clang architecture=arm abi=aapcs address-model=64 binary-format=mach-o [...] "clang++" -o "bin.v2/libs/system/build/clang-darwin-4.2.1/release/abi- aapcs/address-model-64/architecture-arm/threading-multi/libboost_system.dylib" -single_module -dynamiclib -install_name "libboost _system.dylib" "bin.v2/libs/system/build/clang-darwin-4.2.1/release/abi- aapcs/address-model-64/architecture-arm/threading-multi/error_code.o" Despite asking for arm, the "-arch arm64" I would expect is not passed to clang which thus compile to x86_64. However Boost.Context DOES understand I'm targeting arm since it picks the right ASM file: "clang++" -x assembler-with-cpp -O3 -O3 -finline-functions -Wno-inline - Wall -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 - DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DBOOST_SYSTEM_DYN_LINK=1 - DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX - DBOOST_THREAD_USE_DLL=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/clang- darwin-4.2.1/release/abi-aapcs/address-model-64/architecture-arm/threading- multi/asm/make_arm64_aapcs_macho_gas.o" "libs/context/src/asm/make_arm64_aapcs_macho_gas.S" Which yields assembly errors of course since "-arch arm64" is not passed. Other sources seem to manage to build Boost for ARM64 using darwin toolset forcing clang as the compiler and passing many additional options, but their setup fails to build Boost.Context since it either picks the wrong ASM file, either complains the platform is not supported. Thanks in advance ! -- Quentin "mefyl" Hocquet CTO @ infinit.io

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Ambiguous overload for boost::blank when using optional & variant
by Berteun Damman 14 Jan '15

14 Jan '15

Hi, I'm using boost 1.57 after upgrading from 1.50, and the following innocuous looking program does not compile with either GCC (4.9) or Clang (3.5); tested both on Mac & Linux: #include <boost/optional.hpp> // This header triggers the problem #include <boost/variant.hpp> int main() { boost::variant<boost::blank> a, b; swap(a,b); // a.swap(b) does not make a difference } Both GCC and Clang give the same error: /opt/local/include/boost/variant/detail/move.hpp:60:5: error: call to 'swap' is ambiguous swap(lhs, rhs); [....] /opt/local/include/boost/core/swap.hpp:54:8: note: candidate function [with T1 = boost::blank, T2 = boost::blank] void swap(T1& left, T2& right) ^ /opt/local/include/boost/variant/detail/move.hpp:44:13: note: candidate function [with T1 = boost::blank, T2 =boost::blank] inline void swap(T1& lhs, T2& rhs) In this case one could remove the Optional header, but in a larger project this is of course not a solution; a better solution seems to add an overload for swap taking two boost blanks. I feel this is a bug in Boost, can someone confirm and tell me where I should file the bug request? Finally I noticed due to the above error messages that boost::variant will never use variadic templates when you use Clang. For GCC it uses them (in C++11 mode), but for Clang it refuses. Why is this? Thanks, -Berteun

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[Context] Boost.Context ARM64 support
by mefyl 14 Jan '15

14 Jan '15

Hi, We currently use boost context on iOS, and as you may know Apple is making it mandatory for application to bundle a 64bits version starting February 1 (https://developer.apple.com/news/?id=10202014a) It is thus crucial for us - and anyone using Boost Context on iOS - to get a working ARM64 backend working. Looking at github, I see code has been contributed, but the build system still bounces to unsupported.hh when building with clang for ARM64. Is that code acutally working but not-yet-released, or is it still incomplete ? In the latter case, is anyone still working on it and do we have any rough idea of the delay before a working version get pushed ? Happy to read some ARM64 doc and contribute if it's in a stale state, of course. Cheers, -- Quentin "mefyl" Hocquet CTO @ infinit.io

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unit test BOOST_CHECK_CLOSE absolute
by Renaud Lepère 12 Jan '15

12 Jan '15

I am doing unit tests using boost utf but I have sometimes problems with BOOST_CHECK_SMALL because it checks relative value. For example, I am comparing coordinates in 2d spaces and the relative value is not important, the meaningfull value is the absolute difference between coordinates. I have seen that I can do a BOOST_CHECK_SMALL(fabs(x - expected_x), 1e-3); but in this can I don't have a good message when the test fails (it does not show the value of x and the expected_x). In fact I would like to have something like BOOST_CHECK_CLOSE_ABSOLUTE ? Is there something equivalent or how can I do something like this ?

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[GIL] Problem trying to use scoped_channel_value with copy_and_convert_pixels
by Gabriel Marcano 12 Jan '15

12 Jan '15

I have been experimenting with Boost.GIL, and I have run into something that I'm not sure if it's a problem on my end or with Boost.GIL. In essence, I'm trying to make a grayscale image with channels limited to 14 bits. I am using scoped_channel_value to do this. The problem happens when I try to convert the 14 bit image to a 16 bit grayscale image I get compilation errors. I am including the code I am using below: //START CODE #include <boost/gil/gil_all.hpp> #include <cstdint> using namespace std; using namespace boost::gil; namespace detail { struct bits14_min { static std::uint16_t apply() { return 0;} }; struct bits14_max { static std::uint16_t apply() { return 0x3FF;} }; } typedef scoped_channel_value <std::uint16_t, ::detail::bits14_min, ::detail::bits14_max> bits14_t; typedef pixel<bits14_t, gray_layout_t> Pixel1; typedef image<Pixel1> Frame1; int main() { Frame1 image( Frame1::point_t(100, 100), Frame1::value_type((1 << 14)-1), 0); gray16_image_t image2(image.dimensions()); Frame1::view_t view1(view(image)); gray16_image_t::view_t view2(view(image2)); copy_and_convert_pixels(view1, view2); return 0; } //END CODE The interesting thing is that the program compiles if change typedef scoped_channel_value <std::uint16_t, ::detail::bits14_min, ::detail::bits14_max> bits14_t; to typedef scoped_channel_value <float, ::detail::bits14_min, ::detail::bits14_max> bits14_t; I think the relevant error in the log is this: /usr/include/boost/gil/channel_algorithm.hpp:54:8: error: ‘struct boost::gil::scoped_channel_value<short unsigned int, detail::bits14_min, detail::bits14_max>’ is not a valid type for a template non-type parameter struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,-1> {}; I am attaching the full compile log to this email. Thank you for any help with this matter! Sincerely, Gabriel E. Marcano

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