June 2008 - Boost-users - lists.preview.boost.org

[Boost.Test] Looking for Workaround: Subprocesses exiting with 0 reported as fatal error
by Florian Winter 20 Aug '08

20 Aug '08

Hi, Using Boost.Test version 1.35.0, we have run into the following bug http://svn.boost.org/trac/boost/ticket/1723 Is there an easy way to work around or fix this problem in Boost 1.35.0 (such as a patch), so we are not forced to upgrade to the SVN version of Boost.Test? Unfortunately, not starting a sub process is not an option, because it is not our software that starts the sub process but some additional library that we use. In case we have to upgrade to the SVN version of Boost, is there a recent SVN revision or tag that you would consider stable and recommend for use? Thanks in advance for any help. best regards, Florian

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boost on apple gcc 4.2
by Daniel Oberhoff 07 Aug '08

07 Aug '08

Hi, Has anyone successfully used boost with the "new" apple gcc 4.2? I would like to since gcc42 has openmp, but I cant seem to be able to use boost. I compiled and installed boost with apple gcc 4.2 by directly using bjam with --toolset=darwin-4.2. When I try to use it I get an error (detailed output of gcc below) which hints towards problems with inline assembly. Actually, to get it compiled at all I had to set -fasm-blocks. Am I missing a flag of sorts? Or is it "just" another woe with apple's modified assembler? Daniel error message of gcc4.2 with boost::filesystem: In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/path.hpp:19, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/operations.hpp:17, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem.hpp:16, from mmm_fileloader.hpp:12, from mmm_tool_gui.hpp:5, from mmm_tool_gui.cpp:1: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/path.hpp:19, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/operations.hpp:17, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem.hpp:16, from mmm_fileloader.hpp:12, from mmm_tool_gui.hpp:5, from mmm_tool_2.cpp:3: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/archive/shared_ptr_helper.hpp:23, from /opt/boost-gcc4.2/include/boost-1_35/boost/archive/polymorphic_iarchive.hpp:161, from mmm_tool_net.hpp:8, from mmm_tool_net.cpp:1: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token

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[DateTime] 1.35.0: Patch to fix warning
by Peter Klotz 03 Aug '08

03 Aug '08

The attached patch fixes an unused parameter warning in boost/date_time/time.hpp. Best regards, Peter.

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[Conversion] imprecision with lexical_cast from double to std::string
by Andreas Ries 30 Jul '08

30 Jul '08

Hi, I'm using the borland toolset 5.8.2 under Win XP and have a problem doing the following: double val = 795.6352; string result = boost::lexical_cast <string> (val); the resulting string is: "795.63520000000005" with boost 1_35_0 the resulting string is: "795.6352000000001" with boost_1_34_0 Can anybody help?

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Is there a something in boost to facilitate binary buffer transformations into typed data structures/classes?
by Graham Reitz 28 Jul '08

28 Jul '08

I didn't see anything, but I may have missed something. Problem: Binary data is stored in a char buffer from a proprietary device: char* buffer = new char[6]; Data in buffer: [byte 1][byte 2][byte 3][byte 4][byte 5][byte 6] [---16 bit uint--][------------32 bit uint-------------] ...would like to convert to this in a C++'ish style using a boost facility if it exists: (or consider directing me somewhere else if it doesn't) struct // or class { boost::uint16_t first; boost::uint32_t second; } data; I would like to avoid a C-style way of doing this. This seems like something that would have been solved many times. thanks, graham

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Is there an elegant way to initialize an instance of boost::any with a C-style string constant?
by Ferdinand Prantl 10 Jul '08

10 Jul '08

Hello, I would like to ask you about the best solution to initialize a boost::any instance with a C-string constant. Both the most legible (IMHO) possibilities fail: boost::any foo("foo"); boost::any bar; bar = "bar"; Compiler (MSVC 2008 in my case) complains about them: ...\boost\any.hpp(117) : error C2536: 'boost::any::holder<ValueType>::boost::any::holder<ValueType>::held' : cannot specify explicit initializer for arrays with [ ValueType=const char [4] ] ...\boost\any.hpp(134) : see declaration of 'boost::any::holder<ValueType>::held' with [ ValueType=const char [4] ] ...\boost\any.hpp(115) : while compiling class template member function 'boost::any::holder<ValueType>::holder(ValueType (&))' with [ ValueType=const char [4] ] ...\boost\any.hpp(41) : see reference to class template instantiation 'boost::any::holder<ValueType>' being compiled with [ ValueType=const char [4] ] ...\test.cpp(10) : see reference to function template instantiation 'boost::any::any<const char[4]>(ValueType (&))' being compiled with [ ValueType=const char [4] ] Obviously the string constant is considered of the type chat[4] which lacks CopyConstructible and Assignable requirements. Wrapping the constant in some expression which satisfies the requiremenst spoils the beauty of a simple code or brings unnecessary (for the constant handling) object: boost::any foo(static_cast<const char *>("foo")); boost::any foo(std::string("foo")); Such solutions were suggested in the thread http://lists.boost.org/Archives/boost/2003/01/43460.php but I was hoping there could be something better. I suppose there is no way to persuade the compiler to consider the constant to be const char *... Why has not been the following constructor added to boost::any? The array would make it there passing just one conversion: template<typename ValueType> any(const ValueType * value) : content(new holder<const ValueType *>(value)) {} Someone could say that that it is more error prone because it enables storing a pointer which can be invalid as soon as the boost::any instance leaves the scope but the error can be made anyway: boost::any foo(std::string("foo").c_str()); Another possibility would be to match the array type exactly but it has probably no benefit: template<typename ValueType> any(const ValueType value []) : content(new holder<const ValueType *>(value)) {} Do you see any problems with such constructors? How do you use string constants with boost::any? Thank you, Ferda Prantl

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[Boost.Test] Compiling on Mac OS X
by Florian Winter 07 Jul '08

07 Jul '08

Hi, We have run into problems trying to compile Boost.Test on a Mac OS X 10.3 system using GCC version 3.3 (details below). We are using the "included" implementation of Boost.Test in a shared library that we build using our own build system. This works fine on various different platforms and compilers, however part of Boost.Test fails to compile on Mac OS X. We are including Boost.Test in our shared library in the following way: // Define this to declare all Boost.Test symbols as __declspec(dllexport) // rather than __declspec(dllimport). #define BOOST_TEST_SOURCE #define BOOST_TEST_DYN_LINK #include <boost/test/included/unit_test.hpp> The compiler errors (see below) indicate that some symbols related to signal handling are undefined. Either, some required system headers are not included, or these symbols are not portable and not available on Mac OS X (10.3). Has this problem been encountered before? Is there an easy workaround for it, such as defining certain symbols before including the Boost.Test headers? Could it be somehow related to the way we are building Boost.Test? Furthermore, it would be interesting for us to know what the status of Boost.Test on Mac OS X is in general. Unfortunately, the "Portability" section in the documentation http://www.boost.org/doc/libs/1_35_0/libs/test/doc/portability.html as well as the rest of the documentation do not provide a lot of information regarding support for different platforms. Below, you will find the error messages that we got, as well as some information about our system and the version of Boost.Test that we used. Thanks in advance for any help. Best regards, Florian *Boost Version* 1.35.0 *System* MacOSX 10.3 *Compiler* g++ (GCC) 3.3 20030304 (Apple Computer, Inc. build 1666) Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *Errors* In file included from <...>/boost/test/included/unit_test.hpp:22, from <...>:18: <...>/boost/test/impl/execution_monitor.ipp: In member function `void boost::detail::system_signal_exception::report() const': <...>/boost/test/impl/execution_monitor.ipp:286: error: `ILL_ILLOPN' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:286: error: (Each undeclared identifier is reported only once for each function it appears in.) <...>/boost/test/impl/execution_monitor.ipp:291: error: `ILL_ILLADR' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:306: error: `ILL_PRVREG' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:311: error: `ILL_COPROC' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:316: error: `ILL_BADSTK' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:326: error: `FPE_INTDIV' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:331: error: `FPE_INTOVF' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:361: error: `FPE_FLTSUB' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:391: error: `BUS_ADRERR' undeclared (first use this function) <...>/boost/test/impl/execution_monitor.ipp:396: error: `BUS_OBJERR' undeclared (first use this function)

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shared_ptr invalid covariant return type
by John 05 Jul '08

05 Jul '08

This pattern/idiom is well-established: struct A { virtual A* clone () = 0; }; struct B : public A { virtual B* clone (); }; But the above does not work when the pointers A* and B* are replaced by shared_ptr<A> and shared_ptr<B>: struct A { virtual shared_ptr<A> clone () = 0; }; struct B : public A { virtual shared_ptr<B> clone (); }; Is there a workaround? Another way to solve the same problem? Thanks! -John

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Boost::Multi_array and reducing dimensions
by Joey Mukherjee 04 Jul '08

04 Jul '08

I am trying to use boost::multi_array and want to create a view where I am lowering the number of dimensions, but I wish the dimension to be reduced to be decided at runtime. I have a vector of integers and this vector size is the same as the number of dimensions. If the vector [1] value is -1, then the first dimension will have all values (i.e. range ()), otherwise it will be a number indicating what slice to use. You can see in case 2 what I have tried and maybe what I am trying to do. Case 3 and 4 I am hard coding the dimensions where I want all values, which does work, but I'd like to get rid of the hard-codedness and make this more generic. Furthermore, I have a one dimensional array of values which I am "converting" to a boost::multi_array so I can slice into it with the views. I won't know the dimensions until I read the data. Is there a better more generic way of doing this? Something like a pointer to a N-dimensional structure where I can just use the view? Thanks in advance for any ideas! Joey Here is my code: { double ret_val; typedef boost::multi_array_types::index_range range; const VariableInfo &vinfo = GetVariable (si._sensor); SubSensorType local_subsensors (si._subsensors); assert (local_subsensors.size () == vinfo._sizes.size ()); switch (vinfo._sizes.size ()) { case 0 : ret_val = vals [0]; break; case 1 : { // one-d array ret_val = (vals [whichPosition]); } break; // Now we get into slices, find the subsensor element that has -1, and // create a slice along that dimension case 2 : { // two-dimensional array typedef boost::const_multi_array_ref <double, 2> array_type; array_type::index_gen indices; array_type multi_array (&(vals [0]), vinfo._sizes); /* This doesn't work! array_type::const_array_view <1>::type OneDView; if (local_subsensors [0] == -1) OneDView = multi_array [indices [range ()] [local_subsensors [1]]]; else if (local_subsensors [1] == -1) OneDView = multi_array [indices [local_subsensors [0] [range ()]]]; ret_val = (OneDView [whichPosition]); */ } break; case 3 : { // three-dimensional array typedef boost::const_multi_array_ref <double, 3> array_type; array_type::index_gen indices; array_type multi_array (&(vals [0]), vinfo._sizes); array_type::const_array_view <1>::type OneDView = multi_array [indices [local_subsensors [0]] [local_subsensors [1]] [range ()]]; ret_val = (OneDView [whichPosition]); } break; case 4 : { // four-dimensional array typedef boost::const_multi_array_ref <double, 4> array_type; array_type::index_gen indices; array_type multi_array (&(vals [0]), vinfo._sizes); array_type::const_array_view <1>::type OneDView = multi_array [indices [local_subsensors [0]] [local_subsensors [1]] [local_subsensors [2]] [range ()]]; ret_val = (OneDView [whichPosition]); } break; default : assert (vinfo._sizes.size () < 4); } return (ret_val);

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1_36 serialization... another issue...
by Mathieu Peyréga 03 Jul '08

03 Jul '08

Following my previous post... it seems that there are issues with xml too... the 1_35 saved file does not load with 1_36 framework... it seems that the "missing" <item_version>0</item_version> makes the difference.... I hope that may help the developpers... in case i did not misuse the library... Regards, Mathieu -- http://www.incub.net/

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