August 2010 - Boost - lists.boost.org

[format] old-style cast warning
by Jürgen Hunold 25 Aug '10

25 Aug '10

Hi, I'm using Boost.Format with gcc "-Wold-style-cast" enabled. This issued a warning in format/feed_args.hpp. Okay to commit the attached patch ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

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Re: [boost] [1.44] [filesystem] operator +
by Jochen Wilhelmy 25 Aug '10

25 Aug '10

> > Sometimes I have file formats that have two parts, e.g. a description xml > > file > > and a data file. then I'd like to do name + ".xml" and name + ".dat" if name > > is > > a fs::path >path p1 = "foo/bar.xml"; >path p2 = path(p1).replace_extension(".dat"); path p = "foo/bar"; path p1 = p + ".xml";-) path p2 = path(p1).replace_extension(".dat");

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[1.44] [filesystem] operator +
by Jochen Wilhelmy 25 Aug '10

25 Aug '10

> Note that Boost.Filesystem contains functions to retrieve and modify >file extensions. >In my opinion, introducing such a free + operator would be quite bad, as >it would encourage use of it to glue on path segments in ways that may >violate the format of paths for a platform, as in your example of an >unconditional +"/bar", which would be horribly wrong for any platform >that didn't use / as separator. I know that I can exchange the current extension, but how can I add one to a path that soes not have one? The current filename may already contain dots therefore the addition of an extension should not check if there is already one. (e.g. "foo/bar.xy" + ".zw" -> "foo/bar.xy.zw") I don't see any technical problem with + "/bar" since "/bar" is the platform independent notation and should therefore work on any platform. so far it is also allowed to do fs::path("foo/bar") where '/' is also the platform independent separator. therefore it should be equivalent to fs::path("foo") + "/bar". but it would be ok to prevent this e.g. by throwing an exception. something like path.add_extension(".bar") should be ok too. -Jochen

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Boost Test Policy
by Edward Diener 25 Aug '10

25 Aug '10

I was looking at the Boost web page describing the Boost test policies, at http://www.boost.org/development/test.html. I was not sure what I needed to use to design tests for possible Boost software. I noticed that it was not required to use Boost Test in order to do so, but that there was an "Optional (but highly recommended)" section for using Boost Test. But neither of the links there are valid any longer, and while Boost Test still has a Unit Test Framework I did not find any Test Tools section for simple test programs, although perhaps the execution monitors or minimal test in Boost Test was originally meant. Anyway the page needs to be updated in regard to Boost Test links. I also found the lightweigt_test.hpp in Boost detail, so I was wondering whether or not that is now considered a viable enough choice for designing Boost component's tests.

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Compilation error's while building boost 1_44_0 on Solaris (Sun Studio 10)
by Nakul Virmani 25 Aug '10

25 Aug '10

Hi All, I am trying to build boost version 1_44_0 on Solaris.The Solaris box has Sun Studio 10 installed. The compiler details are bash-2.05$ CC -V CC: Sun C++ 5.7 2005/01/07 I am using the following command to build boost libraries *bash-2.05$ bjam --build-dir=/export/home/dfdev/Boost_1_44_0/boost_1_44_0/tmp/build-boost toolset=sun stage* But i get the below compilation errors, not even one of the projects build sun.compile.c++ /export/home/dfdev/Boost_1_44_0/boost_1_44_0/tmp/build-boost/boo st/bin.v2/libs/iostreams/build/sun/release/stdlib-sun-stlport/threading-multi/fi le_descriptor.o Notice: The Early Access serial number will expire in -7 days. In order to purchase the product, visit http://www.sun.com/forte/buy.html or contact your Forte Tools reseller. "libs/iostreams/src/file_descriptor.cpp", line 352: Error: Could not find boost: :shared_ptr<boost::iostreams::detail::file_descriptor_impl>::shared_ptr(boost::i ostreams::detail::file_descriptor_impl*) to initialize pimpl_. "libs/iostreams/src/file_descriptor.cpp", line 355: Error: Could not find boost: :shared_ptr<boost::iostreams::detail::file_descriptor_impl>::shared_ptr(boost::i ostreams::detail::file_descriptor_impl*) to initialize pimpl_. "libs/iostreams/src/file_descriptor.cpp", line 360: Error: Could not find boost: :shared_ptr<boost::iostreams::detail::file_descriptor_impl>::shared_ptr(boost::i ostreams::detail::file_descriptor_impl*) to initialize pimpl_. "libs/iostreams/src/file_descriptor.cpp", line 380: Error: Could not find boost: :shared_ptr<boost::iostreams::detail::file_descriptor_impl>::shared_ptr(boost::i ostreams::detail::file_descriptor_impl*) to initialize pimpl_. "libs/iostreams/src/file_descriptor.cpp", line 385: Error: Could not find boost: :shared_ptr<boost::iostreams::detail::file_descriptor_impl>::shared_ptr(boost::i ostreams::detail::file_descriptor_impl*) to initialize pimpl_. "libs/iostreams/src/file_descriptor.cpp", line 393: Error: Using static_cast to convert from boost::iostreams::file_descriptor_flags to boost::iostreams::detail ::file_descriptor_impl::flags not allowed. 6 Error(s) detected. "CC" -library=stlport4 -xO4 -mt -erroff=%none -KPIC -DBOOST_ALL_NO_LIB=1 -DB OOST_IOSTREAMS_DYN_LINK=1 -DBOOST_IOSTREAMS_USE_DEPRECATED -DNDEBUG -I"." -c -o "/export/home/dfdev/Boost_1_44_0/boost_1_44_0/tmp/build-boost/boost/bin.v2/libs/ iostreams/build/sun/release/stdlib-sun-stlport/threading-multi/file_descriptor.o " "libs/iostreams/src/file_descriptor.cpp" ...failed sun.compile.c++ /export/home/dfdev/Boost_1_44_0/boost_1_44_0/tmp/build -boost/boost/bin.v2/libs/iostreams/build/sun/release/stdlib-sun-stlport/threadin g-multi/file_descriptor.o... sun.compile.c++ /export/home/dfdev/Boost_1_44_0/boost_1_44_0/tmp/build-boost/boo st/bin.v2/libs/iostreams/build/sun/release/stdlib-sun-stlport/threading-multi/ma pped_file.o Notice: The Early Access serial number will expire in -7 days. In order to purchase the product, visit http://www.sun.com/forte/buy.html or contact your Forte Tools reseller. "./boost/type_traits/is_array.hpp", line 41: Error: Multiple declaration for boo st::is_array. "./boost/type_traits/is_array.hpp", line 42: Error: Multiple declaration for boo st::is_array. "./boost/type_traits/is_array.hpp", line 43: Error: Multiple declaration for boo st::is_array. "./boost/type_traits/is_array.hpp", line 44: Error: Multiple declaration for boo st::is_array. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 95: Error: The type of specialized argument boost::mpl::aux::F<boost::mpl::aux::P1> is dependent on another argument. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 95: Error: Partial s pecialization parameter Tag is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 112: Error: Partial specialization parameter F is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 172: Error: The type of specialized argument boost::mpl::aux::F<boost::mpl::aux::P1, boost::mpl::aux ::P2> is dependent on another argument. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 172: Error: Partial specialization parameter Tag is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 189: Error: Partial specialization parameter F is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 254: Error: The type of specialized argument boost::mpl::aux::F<boost::mpl::aux::P1, boost::mpl::aux ::P2, boost::mpl::aux::P3> is dependent on another argument. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 254: Error: Partial specialization parameter Tag is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 271: Error: Partial specialization parameter F is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 339: Error: The type of specialized argument boost::mpl::aux::F<boost::mpl::aux::P1, boost::mpl::aux ::P2, boost::mpl::aux::P3, boost::mpl::aux::P4> is dependent on another argument . "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 339: Error: Partial specialization parameter Tag is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 357: Error: Partial specialization parameter F is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 427: Error: The type of specialized argument boost::mpl::aux::F<boost::mpl::aux::P1, boost::mpl::aux ::P2, boost::mpl::aux::P3, boost::mpl::aux::P4, boost::mpl::aux::P5> is dependen t on another argument. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 427: Error: Partial specialization parameter Tag is not used in the arguments. "./boost/mpl/aux_/preprocessed/plain/full_lambda.hpp", line 445: Error: Partial specialization parameter F is not used in the arguments. "libs/iostreams/src/mapped_file.cpp", line 441: Error: Could not find boost::sha red_ptr<boost::iostreams::detail::mapped_file_impl>::shared_ptr(boost::iostreams ::detail::mapped_file_impl*) to initialize pimpl_. 20 Error(s) detected. Am i missing something? Do i need to do any configuration changes? I will appreciate your input's. Regards, Nakul

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Generic lazy loader library interest
by John Bellone 24 Aug '10

24 Aug '10

Hey guys, Would there be any interest in a generic lazy loader implementation? Thanks, jb

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[1.44] [filesystem] filesystem::path construction problems in version 3
by Adam Badura 24 Aug '10

24 Aug '10

It seems Boost.Filesystem v. 3 in Boost 1.44 has some problems in filesystem::path construction. Firstly it does not work well when a C array is given to the constructor. Problem is illustrated with following code: ---------------------------------------- #include <cstdio> #include <string> #define BOOST_FILESYSTEM_VERSION 3 #include <boost/filesystem.hpp> int main( int argc, char* argv[] ) { char big[100]; char* small = "d:/foo/"; boost::filesystem::path pathFromSmall( small ); pathFromSmall /= "bar.txt"; std::printf( "%s\n", pathFromSmall.string< std::string >().c_str() ); std::strcpy( big, small ); boost::filesystem::path pathFromBig( big ); pathFromBig /= "bar.txt"; std::printf( "%s\n", pathFromBig.string< std::string >().c_str() ); return 0; } ---------------------------------------- Secondly filesystem::path accepts to much in its constructors. Currently it accepts even shared_ptr. This is illustrated by following code which was fine in 1.43 while in 1.44 it results in compilation error (VS 2010) of ambiguous call to "fun". ---------------------------------------- #define BOOST_FILESYSTEM_VERSION 3 #include <boost/filesystem.hpp> #include <boost/smart_ptr.hpp> class Base { }; class Derived : public Base { }; void fun( const boost::filesystem::path& _path ) { } void fun( const boost::shared_ptr< Base >& _pBase ) { } int main( int argc, char* argv[] ) { boost::shared_ptr< Derived > pDerived( new Derived() ); fun( pDerived ); return 0; } ---------------------------------------- Adam Badura

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Re: [boost] [local_function] any interest in a LocalFunction library?
by Pierre Morcello 24 Aug '10

24 Aug '10

> I can implement Boost.LocalFunction macros, which are > similar to your 'V3' macros, in pure C++ ISO standard (no __VA_ARGS__). I > will study your code more. __VA_ARGS__ is iso C99 (but ok not c++). The point is only that boost prefers iso C90, since it is much more widely supported. I have some implementation question on your proposition : how will you detect that 'this' exist, that you are not inside a static function ? If you can do such a thing I am interested to know how you do it (because I did not find out myself) ? My example is trickier than it looks, since it uses the defect 45 of the iso to allow private access for nested classes. This quite unfortunate since the defect 45 is only of statut DR instead of TC1 (which is required for being part of the standard). Best regards, Pierre Morcello

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Re: [boost] [1.44] [filesystem] operator +
by Jochen Wilhelmy 24 Aug '10

24 Aug '10

> > for boost::filesystem::path I would suggest an operator + that works like > > the following > > fs::path("foo") + "bar" -> "foobar" > > fs::path("foo") + "/bar" -> "foo/bar" > > fs::path("foo") / "bar" -> "foo/bar" > > >What's the situation in which you'd like to use that operator? Sometimes I have file formats that have two parts, e.g. a description xml file and a data file. then I'd like to do name + ".xml" and name + ".dat" if name is a fs::path -Jochen

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Re: [boost] [Boost.Locale] Upcoming Boost.Locale version
by Artyom 24 Aug '10

24 Aug '10

> I like to think in terms of [serialized] objects and not strings. > Besides having to internationalize images sometimes I need to do the > same to arrays of strings or any type of object. > In the use case of array of strings, I may in English > have a selection or radii > ["25 miles", "50 miles", "75 miles" "100 miles", "150 miles", "200 miles"]. > However in a different language I may have ["50km", "100km", "150km", >"250km"]. > Because the unit is different I may more or fewer items in the array. > The items in the array may not even be strings but a unit object that has both > >runtime scaler and runtime unit. > There is a general approach to solve such issues, even if this is not supported by the library. You use following: double factor = atof(dgettext("Distance conversion factor for km","1.0").c_str()); int local_distance = static_cast<int>(metric_distance * factor); std::cout <<format(translate("{1,num} kms","{1,num} kms",local_distance)) % local_distance That's it. You just define some translation string and use it as localization reasource. And tanslator translates this factor to ~1.6 and kms to miles according to locale. > So using ICU how would I store and retrieve an array of objects using boost >serialization into one field. For serialization you should always use locale insensitive data. For example metric system. As for time we alawys use POSIX time wich always relates to UTC. > Does ICU support any kind of contenttype, metadata or filename extension that >could identify such items > to tools? Will your Locale library have any add on or enhancement to simplify >this use-case; > > perhaps translate<object type> versus translate? This is done differently. Lets define following: class distance { int meters; }; std::ostream &operator<<(std::ostream &out,distance const &d) { // get stream specific locale std::locale l=out.getloc(); // get stream specific factor double factor = atof(dgettext("Distance conversion factor for km","1.0",l).c_str()); int local_distance = static_cast<int>(metric_distance * factor); // format the distance is stream specific units. out <<format(translate("{1,num} kms","{1,num} kms",local_distance)) % local_distance } Note: locaization is different for serialization and it is wrong way to look on them this way. Serialization is provided for computer-to-computer interface while localization is provided for computer-to-human interface and it is much more compilcated. For example, for serialization of time point it is enought to write it as number representing POSIX time to stream. time_t time_point=time(0); std::cout << time_point; // would be something like 32452345 For human you would write time_t time_point=time(0); std::cout << as::date_time << time_point; // may be something like 03/02/2010 12:30:02 Artyom

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