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[Date Time] time_duration Subsecond Truncation After Construction
by Hossein Haeri 24 Apr '11

24 Apr '11

Dear all, [GCC 4.5.1, MinGW32, WinXPSP3, Boost 1.46.0] I have a simple templatised class which stores references to the passed timestamps. I also have a helper function to ease some syntax awkwardness as follows: template<typename Timestamp> struct Container { Container(const Timestamp& t): t_(t) { cout << "In ctor, t = " << to_simple_string(t) << ", t_ = " << to_simple_string(t_) << endl; } template<typename T1, typename T2> void f(const T1&, const T2&) const { cout << "In f(), t_ = " << to_simple_string(t_); } const Timestamp& t_; }; template<typename Timestamp> Container<Timestamp> container(const Timestamp& t) {return Container<Timestamp>(t);} It happens that, in my release build, the subsecond resolution gets truncated once the passed time duration is stored in my Container. So, for the following code snippet for example container(milliseconds(400)).f(1.1, 2); I get the following nonsense output: In ctor, t = 00:00:00.400000, t_ = 00:00:00.400000 In f(), t_ = 00:00:00 Does anyone here know what's going on? TIA,--Hossein

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[filesystem] get relative path from recursive_directory_iterator
by Ivan Sorokin 24 Apr '11

24 Apr '11

Hello! I'm using boost::filesystem v3. Currently recursive_directory_iterator returns absolute path. So the program for (fs::recursive_directory_iterator it("/home/ivan"); it != fs::recursive_directory_iterator(); ++it) std::cout << *it << std::endl; may output /home/ivan/somedir/1.txt /home/ivan/somedir/2.txt But what I want is something like: ./somedir/1.txt ./somedir/2.txt I use function naive_uncomplete described in https://svn.boost.org/trac/boost/ticket/1976 fs::path base = "/home/ivan"; for (fs::recursive_directory_iterator it(base); it != fs::recursive_directory_iterator(); ++it) std::cout << naive_uncomplete(*it, base) << std::endl; Is there any plans to include this function is boost? Is there any possibility to get relative paths using only functions from boost?

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How to handle blank space in parsing??
by Ramon F Herrera 24 Apr '11

24 Apr '11

Hello all, Boost::regex has been a Godsent to me. Before it, I performed any parsing with Perl. Now I am becoming comfortable with the regex package. (a million thanks to the folks responsible for it, and for Boost in general, btw) My only problem is spaces. I design typical mini computer language syntaxes, for example: Table[1, 4] = Value AND Array[8, 4] My initial approach was to get rid of all spaces before parsing (I recall being taught ages ago that the FORTRAN compiler does just that). Such strategy works in some cases, but the above line would become: Table[1,4]=ValueANDArray[8,4] Which is obviously bad news. I solved this particular case with this syntax: Table[1, 4] = Value && Array[8, 4] My latest "language" looks like this and has the same problem described above: Table rows [1758, 1904, 2053, 2201, 2345, 2497] Table cols [372, 880, 1336, 1756, 2083, 2439] I guess I could insert a colon or something between the first two words, but I am sure there has to be a better way. TIA, -RFH

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[Test] muti-file-test modules and standalone library linking
by Jan Blunck 24 Apr '11

24 Apr '11

Is there a way to write a multi-file-test module in a way that allows me to link it to dynamic and/or a static library version? Currently the software is able to link against a static or a dynamic variant of the boost libraries. If I want to use the boost test framework there seems to be no way how I can build against both variant without changing defines. For the dynamic library variant I would need to define -DBOOST_TEST_ALTERNATIVE_INIT_API while for the static variant I need to use the traditional API. The problem is that the linker in the end decides what library it is linking against. Using the boost/test/included/* variant of the framework does not seem to be supported in a multi-file-test setup. Is there any way I can make this work? Thanks, Jan Jan Blunck Performance Architect RTS Realtime Systems Software GmbH, Rembrandtstrasse 13, D-60596 Frankfurt am Main T: +49.69.61009.0 / F: +49.69.61009.181 Sitz: Frankfurt am Main - HRB 84467 Amtsgericht Frankfurt am Main Geschäftsführer: Steffen Gemuenden, Mark van Vugt www.rtsgroup.net This email and any attachments are for the exclusive and confidential use of the intended recipient. If you are not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, please do not read, distribute or take action in reliance upon this message. If you have received this in error, please notify me immediately by return email and promptly delete this message and its attachments from your computer system.

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boost graph in_edges
by Peter Neher 23 Apr '11

23 Apr '11

hi, i'm using the boost graph library and i'm trying to find the incident edges of one vertex of the following graph: | typedef boost::adjacency_list< boost::vecS, // The container used for egdes boost::vecS, // The container used for vertices boost::bidirectionalS, // bidirectional edges Vertex, // The type that describes a Vertex. Edge // The type that describes an Edge > Graph;| if i try to find the incident edges now, the message "Interpolation failed" is printed. any suggestions? here the code to find the incident edges: |Graph::in_edge_iterator edgeIt, edgeEnd; tie(edgeIt, edgeEnd) = in_edges(vID, m_Graph);| thanks in advance, peter

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[Review] Boost.Convert library, new subversion URL
by Edward Diener 23 Apr '11

23 Apr '11

This is a reminder that formal review of the Boost.Convert library by Vladimir Batov starts today, April 23, and is scheduled to last through May 2. *************** * Its Purpose * *************** The library builds on the past boost::lexical_cast experience, then takes those conversion-related ideas further to suit better today's applications and programing needs. It still offers simple, minimal interface, familiar conversion behavior and additionally provides: * throwing and non-throwing conversion-failure behavior; * support for the default/fallback value to be returned when conversion fails; * two types of the conversion-failure check - basic/simple and better/safe; * formatting support based on the standard std::streams and std::stream-based manipulators (like std::hex, std::scientific, etc.); * support for different locales; * support for boost::range-compliant char and wchar_t-based containers; * no DefaultConstructibility requirement for the Target/Destination type; * consistent framework to uniformly incorporate any type-to-type conversions, extensibility and additional room to grow. With its present support for string-to-type and type-to-string conversions it is an essential tool for applications making extensive use of configuration or MS-Windows-Registry-style files or having to process/prepare considerable amounts of data in, say, XML, etc. More so, it is easily extendable to accommodate, specialize and uniformly deploy new user-defined type-to-type conversions. ******************* * Where to get it * ******************* Normally you can find Boost.Convert here: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-… However because the boostpro web site is having problems and will likely be down for the weekend, I have put the library into the Boost sandbox temporarily, since the Boost sandbox is up. So you can get the library, using Subversion, from https://svn.boost.org/svn/boost/sandbox/convert. This is exactly the same as the vault with the files unzipped. The HTML documentation is part of the distribution and can be found at libs/convert/index.html in the distribution above. ******************** * Writing a review * ******************** The reviews and all comments should be submitted to the developers list, and the email should have "[convert] Review" at the beginning of the subject line to make sure it's not missed. Please explicitly state in your review whether the library should be accepted. The general review checklist: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Edward Diener, Review Manager

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How to prevent boost serialize from object tracking a pointer
by Frank 23 Apr '11

23 Apr '11

Hi all, I have a shared_ptr to an object that changes (the underlying object is non-const, that is, not the shared_ptr), and I'd like to serialize the object each time it changes (size of the archive is not an issue). The problem stems, I think, from object tracking: every time after the first serialization, boost detects that the pointer is the same, and does not write out the (full, updated) object. I've tried putting in BOOST_CLASS_TRACKING(T, boost::serialization::track_never) but it won't compile because there is a BOOST_STATIC_ASSERT in shared_ptr.hpp that prevents setting class T's tracking to track_never if it is then serialized via a shared_ptr, with the comment that "correct shared_ptr serialization depends upon object tracking being used." Am I missing something obvious here, or is another a way to accomplish this? Any help would be greatly appreciated... Thanks, Frank -- View this message in context: http://boost.2283326.n4.nabble.com/How-to-prevent-boost-serialize-from-obje… Sent from the Boost - Users mailing list archive at Nabble.com.

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[fusion] transform and transform_view
by Karsten Ahnert 23 Apr '11

23 Apr '11

Hi, I have a small functor: struct operation { template<class> struct result; template< class F > struct result<F(int)> { typedef long type; }; template< class F > struct result<F(float)> { typedef double type; }; template< class T > typename result< operation(T) >::type operator()( T t ) { typedef typename result< operation(T) >::type result_type; return result_type( t * T( 2 ) ); } }; and I wonder why a transform_view works as expected: typedef fusion::vector< int , float > vector_type; vector_type v( 1 , 3.4 ); fusion::transform_view< vector_type , operation > tv( v , operation() ); while result_of::transform does not: fusion::result_of::transform< vector_type , operation >::type tv2 = fusion::transform( v , operation() ); result in compile errors? Any hints?

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Boost versions and the Interprocess library
by David Ohlemacher 22 Apr '11

22 Apr '11

Hello all, I have a project that is stuck using an old closed src implementation of CORBA that depends on Boost 1.31. Upgrading to a newer version of Boost is not possible. I we have a new requirement that could be partially met using shared memory. Is it possible to use the Interprocess library (first available in Boost 1.35) in our project? I see it only requires the inclusion of a single hdr file, but of course that doesn't mean it would work in a 1.31 environment. Any thoughts would be greatly appreciated. The project is currently using WinXP using Visual Studio 2003. There are much delayed plans to port this to Linux. Thanks, -d -- David Ohlemacher Senior Software Engineer Scientific Solutions Inc. 99 Perimeter Rd Nashua New Hampshire 03063 603-880-3784 . o . . . o o o o

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[units] atan2 functionality with same dimension for y and x
by Ryan 22 Apr '11

22 Apr '11

I found that when I passed atan2 a quantity<si::length> value for both y and x the compiler gave me an error. Upon examination of the atan2 method in "boost/units/cmath.hpp" I found it expected both inputs to atan2 to be dimensionless. The method atan2 can be represented simplistically as atan(y / x). As long as both dimensions to y and x are the same the results is a dimensionless value of (y / x). So shouldn't the inputs to boost::units::atan2 accept any dimension of y and x as long as they are the same? Ryan

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