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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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CVS update
by Victor A. Wagner Jr. 05 Apr '06

05 Apr '06

# Updating sources from CVS (2006-04-04T21:15:00Z)... # Executing CVS command "cvs -d:ssh:vawjr@cvs.sourceforge.net:/cvsroot/boost -z9 update -dPA -r RC_1_34_0" this actually connected and did the update (nothing interesting was retrieved) Victor A. Wagner Jr. http://rudbek.com The five most dangerous words in the English language: "There oughta be a law"

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Boost.Test: violation of min/max guidelines
by John Maddock 04 Apr '06

04 Apr '06

I've just been hit by Boost.Test not following the min/max coding guidelines, the patch is trivial: Index: boost/test/floating_point_comparison.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/test/floating_point_comparison.hpp,v retrieving revision 1.26 diff -r1.26 floating_point_comparison.hpp 66c66 < return std::numeric_limits<FPT>::max(); --- > return (std::numeric_limits<FPT>::max)(); Needs to be applied to the release branch as well now of course :-) Thanks, John.

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[conversion] lexical_cast size optimization
by Alexander Nasonov 04 Apr '06

04 Apr '06

I noticed that instantiated lexical_cast functions are parameterized with array types. It's not optimal as array_to_pointer_decay is applied to argument type immediately and original type is not user anywhere else. My idea is to define inlined lexical_cast that just transforms the argument type and forward a call to detail::lexical_cast: template<typename Target, typename Source> inline Target lexical_cast(const Source &arg) { typedef typename detail::array_to_pointer_decay<Source>::type NewSource; return detail::lexical_cast<Target,NewSource>(arg); } The detail::lexical_cast is almost an original lexical_cast except that it doesn't transform the argument type. Additionally, call_traits<>::value_type can be applied to the argument type: namespace detail { template<typename Target, typename Source> Target lexical_cast( BOOST_DEDUCED_TYPENAME boost::call_traits<Source>::value_type arg) { detail::lexical_stream<Target, Source> interpreter; Target result; if(!(interpreter << arg && interpreter >> result)) throw_exception(bad_lexical_cast(typeid(Source), typeid(Target))); return result; } } I tested lexical_cast_test.cpp with gcc 3.4.4 [FreeBSD] 20050518. Code was generated with bjam --v2 release. Original size: 220316 Optimized: 201940 -17.95K ( 8.34% ) Optimized & call_traits: 197108 -22.66K ( 10.54% ) Additional transfomations can be applied. For example, enums can be promoted to integral types. I'm a bit unsure about this, though. This change could break enum types that have overloaded operator<<. What is expected behavior in this case? -- Alexander Nasonov

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