July 2005 - Boost - lists.boost.org

[serialization] Why can't hyphens appear in NVP's?
by Jonathan Turkanis 21 Jul '05

21 Jul '05

Hi, I'm using the serialization library for the first time. Everything works pretty nicely, but I'm a little surprised that I can't use hyphens in the first component of a name-value pair. What's the purpose of this restriction? As long as the hyphen is not the first character of a name, it should correspond to perfectly legal XML. Jonathan

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Re: [boost] Regressions in your Boost libraries as of 2005-07-13
by Jens Maurer 21 Jul '05

21 Jul '05

Douglas Gregor wrote: > You are receiving this report because one or more of the libraries you > maintain has regression test failures that are not accounted for. > A full version of the report is sent to the Boost developer's mailing > list. > > Detailed report: > http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… > > There are failures in these libraries you maintain: > random (2) > > |random| > random_test: intel-win32-8_1 intel-win32-8_1 I'm sorry, but I think I can't do anything about that. I can only imagine there is an optimization issue here, but I don't have Windows and thus can't test the Windows compiler. :-/ Jens Maurer

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[serialization] using non-intrusive load and save
by Jonathan Turkanis 21 Jul '05

21 Jul '05

Hi, What's the recommended way to spit non-intrusive serialization into two functions? It looks like I could use tag dispatch with the nested metafunction is_saving or is_loading, but I want to give a very simple example of non-intrusive serialization. Also, is there any reason that instances of these metafunctions aren't convertible to bool, like the boolean metafunctions from type_traits and mpl? Jonathan

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Minor bug in shared_ptr documentation
by Joe Gottman 21 Jul '05

21 Jul '05

The documentation for the shared_ptr default constructor has the following sentence in the Effects clause: "Empty shared_ptr objects have an unspecified use_count." This is no longer true, since the default constructor now includes the postcondition that use_count() == 0. Joe Gottman

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Re: [boost] Interest in a binary_int template for binary literals?
by Scott Schurr 21 Jul '05

21 Jul '05

Greetings, I've placed the binary_int template in the Boost sandbox at Sourceforge. I've also included a crude unit test and a rough shot at documentation. I'd like to thank Pavel Vozenilek for his improvements on the template and for his guidance through the Boost process. I'm going to be on vacation for the next week (until July 25th). So if you send comments I'll get back to you after I return. Thanks for your attention. Scott Schurr

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compile time version of double
by Peder Holt 20 Jul '05

20 Jul '05

I have now completed a compile time version of double which (as far as I have been able to test) the same results as the runtime equivalent. I have implemented mpl-support for all arithmetic operations plus all comparison operations. To test the accuracy, I have tested it against Cromwells sine-implementation (which by the way had a bug: In stead of 1-(angle*angle*/((2*i+2)*(2*i+3))*next_term it had (angle*angle*/((2*i+2)*(2*i+3))*next_term-1) and got the same result as a runtime-equivalent implementation of the same algorithm. There are four ways to construct a double: integral_to_double<mpl::int_<-355> > or integral_c_to_double<int,-355>::type string_c_to_double<3,'.',1,4,1,5,9,2,6,5,3,5,8,9,7,9,3,2,3,8,4,6,2,6,4,3,3,8,3,2,7,9> typedef BOOST_DOUBLE(3.141592653589793238462643383279502884197169399375105820974944592) pi; double_<mantissa<0x6487ed51,0x085a3000>,1,0> <-Equivalent of pi. The algorithm behind string_c_to_double is not very efficient, so if anyone has a better idea for an implementation, feel free to contribute :) BOOST_DOUBLE is a non-compliant macro that relies on compile time behaviour of floating operations. I have not yet added code to handle +-infinity,QNan,and SNan, but this is relatively easy. 0.0 is not represented correctly (has wrong exponent when converted to double) +0.0 does not equal -0.0 yet. On the upside, this implementation uses a 61 bit mantissa, so it is possible to utilize the full mantissa without rounding when calculating e.g. sine. This is done using boost::metamath::detail::plus_double_double<a,b>::type boost::metamath::detail::times_double_double<a,b>::type boost::metamath::detail::divides_double_double<a,b>::type The user should then deal with rounding before returning the final value: boost::metamath::detail::round<a>::type; or boost::metamath::detail::cutoff<a>::type; if no rounding is wanted. The source is available from the vault: http://boost-sandbox.sourceforge.net/vault/ <metamath.zip> Regards, Peder Holt

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Boost regression notification (2005-07-20)
by Douglas Gregor 20 Jul '05

20 Jul '05

Boost regression test failures ------------------------------ Report time: 2005-07-20T14:32:43Z This report lists all regression test failures on release platforms. Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… 135 failures in 10 libraries: filesystem (2) multi_index (1) program_options (5) random (2) serialization (110) spirit (1) test (5) thread (1) variant (1) wave (7) |filesystem| operations_test_dll: borland-5_6_4 path_test_dll: borland-5_6_4 |multi_index| test_special_list_ops: vc-8_0 |program_options| cmdline_test_dll: mingw-3_4_2 positional_options_test_dll: mingw-3_4_2 unicode_test_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_3-darwin |random| random_test: intel-win32-8_1 intel-win32-8_1 |serialization| test_class_info_load_binary_archive: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_binary_archive_dll: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_archive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_archive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_warchive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_warchive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux vc-6_5 test_class_info_load_xml_archive: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_archive_dll: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_warchive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_warchive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_const_load_fail1: borland-5_6_4 test_const_load_fail1_nvp: borland-5_6_4 test_const_load_fail2: borland-5_6_4 test_const_load_fail2_nvp: borland-5_6_4 test_const_save_fail1: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_const_save_fail2: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_const_save_fail3: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_demo_dll: cw-9_4 cw-9_4 test_demo_exception_dll: cw-9_4 cw-9_4 test_demo_fast_archive_dll: msvc vc-6_5 test_demo_pimpl_dll: msvc vc-6_5 vc-7_0 test_demo_portable_archive: intel-win32-8_1 intel-win32-8_1 vc-7_0 test_demo_portable_archive_dll: borland-5_6_4 intel-win32-8_1 intel-win32-8_1 test_demo_shared_ptr: cw-9_4 cw-9_4 cw-9_5-darwin test_demo_shared_ptr_dll: cw-9_4 cw-9_4 cw-9_5-darwin msvc vc-6_5 vc-7_0 test_diamond_binary_archive: cw-8_3 cw-9_5-darwin test_diamond_binary_archive_dll: cw-9_5-darwin test_diamond_text_archive: cw-8_3 cw-9_5-darwin test_diamond_text_archive_dll: cw-9_5-darwin test_diamond_text_warchive: cw-8_3 cw-9_5-darwin test_diamond_text_warchive_dll: cw-9_5-darwin test_diamond_xml_archive: cw-8_3 cw-9_5-darwin test_diamond_xml_archive_dll: cw-9_5-darwin test_diamond_xml_warchive: cw-8_3 cw-9_5-darwin test_diamond_xml_warchive_dll: cw-9_5-darwin test_map_binary_archive_dll: msvc vc-6_5 vc-7_0 test_map_text_archive_dll: msvc vc-6_5 vc-7_0 test_map_text_warchive_dll: msvc vc-6_5 vc-7_0 test_mult_archive_types: cw-9_4 cw-9_4 cw-9_5-darwin test_mult_archive_types_dll: cw-9_4 cw-9_4 cw-9_5-darwin msvc vc-6_5 test_non_default_ctor_text_archive_dll: cw-9_5-darwin test_non_default_ctor_text_warchive_dll: cw-9_5-darwin test_non_default_ctor_xml_archive_dll: cw-9_5-darwin test_non_default_ctor_xml_warchive_dll: cw-9_5-darwin test_non_intrusive_text_archive_dll: cw-9_5-darwin test_non_intrusive_text_warchive_dll: cw-9_5-darwin test_non_intrusive_xml_archive_dll: cw-9_5-darwin test_non_intrusive_xml_warchive_dll: cw-9_5-darwin test_registered_xml_archive: intel-win32-8_1 test_shared_ptr_132_binary_archive_dll: intel-win32-8_1 test_variant_binary_archive: vc-8_0 |spirit| owi_mt_tests: gcc-3_3-darwin |test| errors_handling_test: cw-9_5-darwin test_fp_comparisons: borland-5_6_4 test_tools_test: cw-9_4 cw-9_4 cw-9_5-darwin |thread| test_thread: cw-8_3 |variant| variant_test5: gcc-3.2.3-linux |wave| test_re2c_lexer: vc-8_0 test_slex_lexer: vc-8_0 testwave: cw-8_3 cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux vc-8_0

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Re: [boost] New Library Proposal: dual_state
by Jost, Andrew 20 Jul '05

20 Jul '05

> -----Original Message----- > From: boost-bounces(a)lists.boost.org > [mailto:boost-bounces@lists.boost.org] On Behalf Of Rob Stewart > From: "Jost, Andrew" <Andrew_Jost(a)mentor.com> > > From: boost-bounces(a)lists.boost.org <clip> > > example code (BTW, others seem to prefer the spelling > "adaptor," which > > is more consistent with other standardized names like > "iterator," so > > I'll conform to that): > > I took a look at "adapter" and "adaptor" at dictionary.com. > Most dictionaries list "adapter" as the main entry and > "adaptor" as a variant. WordNet at Princeton University > makes the two synonymous only for this usage. > > A quick Google search showed 18.2 million hits for "adapter" and > 4.1 million for "adaptor." > > I think "adapter" is the right spelling in this case. > I also checked dictionary.com and came to the same initial conclusion, but so many people used "adaptor" in their replies that it made me wonder whether that spelling was more appropriate. I prefer whichever spelling is intuitive for most users. <clip> > > > // METHOD #2a: define a custom predicate template< class T, class > > Pred, T Def = T() > class optPred : public > > std::binary_function<boost::optional<T>, > > boost::optional<T>, bool> { > > Pred f; > > T _eval( const boost::optional<T>& x ) const { > > return ( x ? x.get() : Def ); > > } > > public: > > optPred() : f( Pred() ) {} > > bool operator()( const first_argument_type& a, const > > second_argument_type& b ) const { > > return f( _eval(a), _eval(b) ); > > } > > }; > > opt_int opt_max; > > opt_max= *std::max_element( v.begin(), v.end(), optPred< int, > > std::less<int>, -1 >() ); > > That's a lot of work. You'd want to use something like > Boost.Lambda to make this more reasonable. > Yes, way too much work. See below. > > // METHOD #2b: use an adaptor-like predicate template< > class T > class > > adaptor_substitute : public std::unary_function< > boost::optional<T>, T > > > { > > T Def; > > public: > > _adaptor_() : Def( T() ) {} > > _adaptor_(T def) : Def( def ) {} > > T operator()(const argument_type& x ) { > > return ( x ? x.get() : Def ); > > } > > }; > > max = *std::max_element( > > boost::make_transform_iterator( v.begin, > > adaptor_substitute<int>(-1) ), > > boost::make_transform_iterator( v.end, > adaptor_substitute<int>(-1) > > ) > > ); > > This isn't really an adapter substitute. It is an adapter, > adapted (pun intended) to be a predicate. > But a predicate must return bool, not T. Did I miss something? > > // METHOD #3: use an adaptor > > max = *std::max_element( > > boost::make_transform_iterator( v.begin, > > boost::optional<int>::adaptor(-1) ), // NOTE: > > boost::optional<int>::adaptor does not currently exist > > boost::make_transform_iterator( v.end, > > boost::optional<int>::adaptor(-1) ) > > ); > > That is clearly the most straightforward of the bunch, but > I'd like to see a proper Boost.Lambda or Boost.Function > variant for comparison. > I would prefer to use Boost.Lambda, but I am currently stuck on VC6 for Win32 development. It is becoming a problem... > BTW, why have you shown the adapter as a nested type of > boost::optional? Do you not think it is applicable to > anything else? I can envision adapting pointers or even > floating point types (where NaN is the "empty" value), to > name just two more types adapter might support. I guess I started with Boost.Optional in mind and never considered anything else. Also, depending on the implementation the adapter may need to interact with Boost.Optional. Can you provide examples of some ways you might use an adapted pointer or float? -Andy

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[parameter] Preliminary Reference Checked In
by David Abrahams 20 Jul '05

20 Jul '05

Before he went away for the week, Daniel Wallin was working on the reference docs. I checked in what he had done so far (libs/parameter/doc/html/reference.html), and embedded comments in the .rst file at libs/parameter/doc/reference.rst. I got about halfway through the document adding comments. It might be helpful to Daniel to finish quickly when he gets back if some other people felt like picking up the editorial commenting. IMO it's still quite rough, so be warned -- it may not be easy. Also, please read my embedded comments to get an idea of the direction I'm going in before you start adding yours. Regards, -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Interest in Graph Clustering Algorithms
by Eric Breimer 20 Jul '05

20 Jul '05

We are interested in submitting a collection of novel graph clustering algorithms to the Boost Graph Library and we wanted to see if there was any interest. Unlike conventional clustering algorithms that partition a graph into disjoint subsets, our algorithms efficiently compute locally optimal dense subsets. This can lead to overlapping clusters, which has advantages in many applications. The algorithms have been shown to work effectively on both synthetic and real-world graphs, and also have been shown to outperform well-known k-neighborhood heuristics. See: 1. http://www.cs.rpi.edu/~goldberg/publications/isi-05-clust.pdf 2. http://www.cs.rpi.edu/~goldberg/publications/iadis-clus.doc The algorithms are truly general-purpose. They work on any type of graph; A user only needs to supply a density metric. A density metric can factor the size of the cluster to help control or regulate the size of the desired clusters. We have efficient algorithms for creating an initial set of clusters based on a given density metric, and we have efficient algorithms that can refine and optimize the density of an existing set of clusters.

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