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bug: cyclic header dependencies in type_traits
by Scott McPeak 06 Apr '06

06 Apr '06

In Boost 1.33.1, the following headers are involved in an #inclusion cycle: boost/type_traits/is_scalar.hpp boost/type_traits/is_enum.hpp boost/type_traits/is_convertible.hpp boost/type_traits/is_abstract.hpp boost/type_traits/is_class.hpp This causes a problem for standards-compliant compilers because, depending on where you enter the cycle, some template's declaration will not be seen before it is used. For example, entering at is_scalar.hpp (which happens when you include optional.hpp) causes the definition of is_class<> to be seen before the declaration of is_scalar<>, but the former uses the later. The problem was introduced in the change from 1.32 to 1.33, when is_abstract.hpp started being #included by is_convertible.hpp. For reasons I still don't fully understand, this doesn't always actually cause a problem. I think it has to do with the mysterious BOOST_NO_IS_ABSTRACT macro; my understanding of the intricacies of Boost configuration is very limited. The place I ran into this was using an EDG-based front end to parse the preprocessed output of Sun CC 5.7 on solaris-sparc; input is "#include <boost/optional.hpp>"; using Boost 1.33.0 or 1.33.1. I can't repro on linux or with gcc, nor with the latest CVS version of Boost. But regardless, the cycle is still present in the latest CVS, and cyclic header dependencies are usually a bug. -Scott

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Ann: Statistics/Special Functions/Numeric Methods Toolkit
by John Maddock 06 Apr '06

06 Apr '06

Gentlemen, This is to announce a new library added to the file vault, it is a work in progress and is intended to fulfil two needs: 1) To provide a small number of high quality special functions, initially these will be concentrated on functions used in statistical applications (with a strong nod towards Paul Bristow's existing work in this area). The functions currently implemented are the gamma/beta/erf functions along with the incomplete gamma and beta functions (four variants of each). All the implementations are fully generic and support the use of arbitrary "real-number" types, although they are optimised for use with types with known-about mantissa sizes: typically float, double or long double. Use of these functions with interval arithmetic (Boost.Interval) isn't quite supported yet, but it's something I want to investigate soon. 2) To provide at least some of the tools required to implement mathematical special functions, hopefully the presence of these will encourage other authors to contribute more special function implementations in the future. Currently implemented are helpers for the evaluation of infinite series, continued fractions and rational approximations. There are also classes for the manipulation of polynomials, for testing a special function against tabulated test data, and for the rapid generation of test data and/or data for output to an external graphing application. I've been keeping deliberately quiet about this for a while (with apologies to Paul Bristow), as I wanted to be certain that these special function implementations would offer something over and above what is available elsewhere. I still have some way to go here: erf and lgamma in particular still need work, but the incomplete gamma and beta functions already typically have 10 times lower error bounds than Cephes and GSL, and in one spectacular case 10^11 times more accurate (which is to say there is a domain of the incomplete gamma where Cephes and GSL have hardly any significant digits correct). Preliminary documentation is available here: http://www.johnmaddock.co.uk/toolkit and includes quite a lot of information already, including descriptions of implementation methodologies etc. There's also a roadmap of future work, open issues, and what needs to be done before a final release etc: http://www.johnmaddock.co.uk/toolkit/libs/math/doc/html/math_toolkit/status… The actual source code, is available for download in the vault: http://boost-consulting.com/vault/index.php?action=downloadfile&filename=ma… Regards, John Maddock.

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[Bug] Interaction between date_time and filesystem libraries
by Joe Gottman 06 Apr '06

06 Apr '06

When I try to the following code under VC6.0: #include <boost/date_time/gregorian/greg_date.hpp> #include <boost/filesystem/convenience.hpp> I get the following error: error C2955: 'equivalent' : use of class template requires template argument list : see declaration of 'equivalent' If I reverse the order of inclusion there is no error. Joe Gottman

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[tuples] const_tie
by Yuval Ronen 05 Apr '06

05 Apr '06

Hi. In the tuples library there is a function that creates a tuple with auto deduction of types - make_tuple(), and there's also a function that creates a tuple with reference of auto deduction of types - tie(), but there's no function that does the same with const reference. I found that such a function is useful when I have a simple struct with simple members, and I want comparision operators to it. Instead of writing these operators myself, I'd like to use tuples' code that does it. To ease this task (IOW, to save me specifying the tuple type explicitly) a const_tie would be most useful. my code would then look like: #define MY_STRUCT_AS_TUPLE(obj) const_tie(obj.x, obj.y, obj.z) bool operator<(const MyStruct &lhs, const MyStruct &rhs) { return MY_STRUCT_AS_TUPLE(lhs) < MY_STRUCT_AS_TUPLE(rhs); } which is the best I can think of (with typeof I could also turn the macro to a template function). I know I can accomplish the same with make_tuple() and cref(), but this way I can avoid the repetitive cref() calls. Can this be added? Thanks, Yuval

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MSVC doesn't like some high-ASCII characters on non-US systems
by Foster Brereton 05 Apr '06

05 Apr '06

All, We are getting warnings when trying to compile Boost source files with MSVC 2003 and 2005 when there are high-ASCII characters in the sources. The reported problem only shows up when the computer's region is set to Japanese, but there could be other affected regions as well. A viable workaround is changing the setting for non-Unicode programs in the Control Panel/Regional and Language Options from Japanese to English (United States), but this is very inconvenient for members of our staff whose native region is Japanese. One (abridged) example of the warning we get from MSVC is: While compiling boost\type_traits\is_base_and_derived.hpp: warning C4819: The file contains a character that cannot be represented in the current code page (932). Save the file in Unicode format to prevent data loss. A caveat to this problem is that the warning shows up when there are high-ASCII characters in comments, so all copyright symbols and high-ASCII characters used in names have the potential to generate these compilation warnings for us. Another caveat to this problem is not all high-ASCII characters produce this problem. My guess is that some of the high-ASCII characters have a valid code page translation (e.g., the copyright symbol), and so the warning is not emitted. An implication of this would be that some characters will work for some OS regions and not for others, resulting in a varied set of errors based on the region one has chosen. The reason this is a problem is because our projects have warnings-as-errors turned on. We are not interested in disabling warnings-as-errors to mitigate the issue because of the far-reaching side effects of such a change. Has anyone else seen this problem? Are there other potential fixes other than removing all high-ASCII characters from the source files? Blessings, Foster -- Foster T. Brereton - Computer Scientist Software Technology Lab, Adobe Systems Incorporated fbrereto(a)adobe.com -- http://opensource.adobe.com

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Attempting to build doc for sandbox project failure
by Edward Diener 05 Apr '06

05 Apr '06

I have setup BoostBook on my system following the instructions at Boost in the BoostBook documentation. I attempted to generate documentation for one of the sandbox projects, going to the dandbox project's libs/doc directory and executing bjam --v2 there. I received a message saying that "error: Did not find Jamfile or project-root.jam in any parent directory." But I can clearly see a Jamfile in the sandboxes root directory. Does anybod have any idea what has gone wrong ?

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[Serialization] Segfaults on invalid input
by Michael Gebetsroither 05 Apr '06

05 Apr '06

Hi all, I've played a bit with boost::serialize and discoverd two problems (one segfault and one maybe related memeory exhaustion). Segfault: demo_xml from boost::serialize examples. I've changed the output format to text_archiv. If i increase the length of a string in the text_archiv by 2, it gives a segfault. All files could be found at: http://einsteinmg.dyndns.org/projects/boost_segf. - valgrind output (demo_xml.log) - gdb backtrace (demo_xml_gdb_backtrace) - normal input file (demo.txt) - input file which results in segfault (demoin.txt) I changed the length of the string "24th Street" from 11 to 13 same results for other strings. - demo_xml (compiled with -O2 -g3 for x86-32 gnu/linux, gcc 4.0.3-1) - the core file (core.gz) - and the sourcefiles demo_xml.{hpp,cpp} Memory exhaustion: Shows a similar problem, but with a very simple testobject (with just 2 std::string's). The output of this program should only 4 small lines but is 130MB (many printed \0). All files could be found at: http://einsteinmg.dyndns.org/projects/boost_memex - valgrind output (ser.log.gz, is 67MB unzipped) - program output with false input file (ser_false_output.gz, ~130MB unzipped) - normal output file (ser_out.txt) - evil input file (ser_in.txt) the length of the first string ("test1") is incremented by 2 - ser (compiled with -O2 -g3 for x86-32 gnu/linux, gcc 4.0.3-1) Boost version is 1.33.1. Hope that helps, solving this bug. Greetings, Michael Gebetsroither

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[Boost-bugs] [ boost-Bugs-1464566 ] uniform_01 copies engine instead of using a reference
by SourceForge.net 05 Apr '06

05 Apr '06

Bugs item #1464566, was opened at 2006-04-04 19:31 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1464566&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: random Group: None Status: Open Resolution: None Priority: 5 Submitted By: Hubert Chan (uhoreg) Assigned to: Jens Maurer (jmaurer) Summary: uniform_01 copies engine instead of using a reference Initial Comment: In the uniform_01 class, the constructor takes a base_type (i.e. the random number generator) as its argument, and the _rng member is just a base_type. This results in uniform_01 copying the random number generator, along with its state. Thus if one creates several uniform_01 objects (e.g. one at the beginning of each of several functions), they will all return the same random numbers. The constructor should take a reference (i.e. base_type&) as its argument, and the _rng member should be a base_type&. (Indeed, the documentation at http://www.boost.org/libs/random/random-distributions.html#uniform_01 says that the constructor takes a base_type&.) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1464566&group_… ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[review] promotion traits - reminder
by Tobias Schwinger 05 Apr '06

05 Apr '06

Dear users & members of Boost, half of the scheduled review period is over and there were no reviews, so far. Therefore I want to welcome you, once again, to evaluate the proposed Boost software. The end of the review period is scheduled for April 6, so please try to post your review before then. Download URL ============ http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz About the submission ==================== The Promotion Traits extend Boost.TypeTraits with templates that compute the type after promotion has been applied. Example: // given template<typename T> struct some_algorithm; template<> struct some_algorithm<int> { [...] }; // [...] more specializations // , [...] some_algorithm< typename integral_promotion<T>::type > [...] // makes some_algorithm work for any type T that promotes to an integer // (that is enums and smaller integral types) without the need for // additional specialization It's a small submission so you probably won't notice that you're working before you're done... Review questions ================ Please always explicitly state in your review, whether you think the library should be accepted into Boost. You might want to comment on the following questions: - 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? Regards, Tobias (Review Manager)

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[review] promotion traits
by Tobias Schwinger 05 Apr '06

05 Apr '06

The review of Alexander Nasonov's Promotion Traits start today. Since it's a small contribution it will be fast-track reviewed and the end of the review period is scheduled for April 6. Download URL ============ http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz About the submission ==================== The Promotion Traits extend Boost.TypeTraits with templates that compute the type after promotion has been applied. Example: // given template<typename T> struct some_algorithm; template<> struct some_algorithm<int> { [...] }; // [...] more specializations // , [...] some_algorithm< typename integral_promotion<T>::type > [...] // makes some_algorithm work for any type T that promotes to an integer // (that is enums and smaller integral types) without the need for // additional specialization Review questions ================ Please always explicitly state in your review, whether you think the library should be accepted into Boost. You might want to comment on the following questions: - 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? Regards, Tobias (Review Manager)

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