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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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Boost regression notification (2005-07-19)
by Douglas Gregor 20 Jul '05

20 Jul '05

Boost regression test failures ------------------------------ Report time: 2005-07-19T15:08:59Z This report lists all regression test failures on release platforms. WARNING: The following libraries have failing regression tests but do not have a maintainer on file. Once a maintainer is found, add an entry to libs/maintainers.txt to eliminate this message. io Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… 143 failures in 11 libraries: filesystem (4) io (1) lambda (1) multi_index (5) parameter (1) program_options (5) random (2) serialization (110) spirit (1) test (6) wave (7) |filesystem| operations_test_dll: borland-5_6_4 mingw-3_4_2 path_test_dll: borland-5_6_4 mingw-3_4_2 |io| ios_state_unit_test: intel-win32-8_1 |lambda| exception_test: vc-8_0 |multi_index| test_basic: intel-win32-8_1 test_mpl_ops: intel-win32-8_1 test_range: intel-win32-8_1 test_set_ops: intel-win32-8_1 test_update: intel-win32-8_1 |parameter| sfinae: cw-8_3 |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 vc-7_1 vc-8_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_list_text_archive: vc-8_0 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 |spirit| owi_mt_tests: gcc-3_3-darwin |test| errors_handling_test: cw-9_5-darwin vc-8_0 test_fp_comparisons: borland-5_6_4 test_tools_test: cw-9_4 cw-9_4 cw-9_5-darwin |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] Boost.Filesystem i18n mini-review
by Jan Hermelink 20 Jul '05

20 Jul '05

Russell Hind wrote: > Peter Dimov wrote: >> >> No. 8.3 aliases are optional on NTFS and turning them off improves >> the performance of the file system, sometimes significantly. >> > > Do you have any links to documentation on this (MSDN or whatever?) I > didn't realise you could disable that feature and would be interested > to > read about the advantages/disadvantages of doing so. Sorry, no link. Bit I have described the registry value for this in my other post. You also can use the "fsutil" command: fsutil.exe behavior query disable8dot3 queries your setting, and fsutil.exe behavior set disable8dot3 1 disables 8.3 alias generation. Jan

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Re: [boost] Boost.Filesystem i18n mini-review
by Jan Hermelink 20 Jul '05

20 Jul '05

This is not (yet) a review, but I use your filesystem library in several unicode projects and am very interested in the wide char implementation. I have tried wpath and wpath_directory_iterator with two projects and run in several minor problems: - Building I can't build the DLLs on my system (Windows XP SP2, VC 7.1): path.cpp(51) : error C2491: 'boost::filesystem::wpath_traits::imbue' : definition of dllimport function not allowed Static builds run fine. - fstream.hpp: Declaration of function narrow_path(const std::wstring & file_ph, ...) If several filesystem fstream objects are declared in different translation units, the linker complains this symbol as multiple defined. Adding an inline specifier helps as workaround. - fstream.hpp: Implementation of function narrow_path(const std::wstring & file_ph, ...) This function doesn't work at all on my system, it returns always the empty string. Why is this 8.3 conversion needed, can this work on NTFS reliable? Replacing the current implementation thru a simple narrow conversion helps as workaround. - is_symlink() Why isn't this function implemented on Windows? A NTFS junction is symlink, isn't it? After fixing the above problems the library seems to run fine. Thank you for your work! Jan

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Re: [boost] Boost.Filesystem i18n mini-review
by Jan Hermelink 20 Jul '05

20 Jul '05

Peter Dimov wrote: > Jan Hermelink wrote: > >> - fstream.hpp: >> Implementation of function narrow_path(const std::wstring & >> file_ph, ...) This function doesn't work at all on my system, it >> returns always the empty string. Why is this 8.3 conversion needed, >> can this work on NTFS reliable? > > No. 8.3 aliases are optional on NTFS and turning them off improves the > performance of the file system, sometimes significantly. Now I remember it: In fact I have turned off the 8.3 aliases for my machine months ago. I have set the registry value NtfsDisable8Dot3NameCreation (HKLM\System\CurrentControlSet\Control\FileSystem) to 1. Jan

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[config] Why is BOOST_HAS_LONG_LONG defined in suffix.hpp?
by Markus Schöpflin 20 Jul '05

20 Jul '05

The first few lines of suffix.hpp currently look like this: #include <limits.h> # if !defined(BOOST_HAS_LONG_LONG) \ && !defined(BOOST_MSVC) && !defined(__BORLANDC__) \ && (defined(ULLONG_MAX) || defined(ULONG_LONG_MAX) || defined(ULONGLONG_MAX)) # define BOOST_HAS_LONG_LONG #endif What is the reason for this code being there? Isn't it enough to test for this in the platform/compiler/stdlib config? I'm asking this question because currently stdlib/libstdcpp3.hpp explicitely turns off BOOST_HAS_LONG_LONG when the library indicates that there is no support for long long, and this is foiled by the code in suffix.hpp, which turns on BOOST_HAS_LONG_LONG again. (And this causes errors with gcc-3.3.x on Tru64.) Maybe we need two config macros for this? One for BOOST_COMPILER_HAS_LONG_LONG, and one for BOOST_STDLIB_HAS_LONG_LONG? Comments or thoughts, anyone? Markus

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Re: [boost] multi_array 64-bit patch
by Thomas Klimpel 19 Jul '05

19 Jul '05

Ronald Garcia wrote: > I made the changes you show below thanks > with the exception of the switch to ptrdiff_t for the index type. > It's not obvious to me that that is the correct change to make I have to admit that the name "std::ptrdiff_t" sounds strange in the context of "index", but there are some container classes in boost that use std::ptrdiff_t as the argument type for operator[], "boost::scoped_array" and "boost::shared_array" for example. And I think "std::ptrdiff_t" makes perfect sense as the index type for an operator[] that accepts both negative and positive integers. There might be types with more comforting names like typedef boost::intmax_t index; // from "boost/cstdint.hpp" typedef boost::detail::integer_traits<std::size_t>::difference_type index; // from "boost/detail/numeric_traits.hpp" typedef intmax_t index; typedef intptr_t index; but "intmax_t" and "intptr_t" seem to be more part of the "c standard" than of the "c++ standard", and the boost types don't help me with the annoying warnings on 32-bit windows with Visual C++.NET. On 32-bit windows, size_t is defined as "typedef _W64 unsigned int size_t;" where the _W64 just means that I will get warning messages, if I convert this type to a type without _W64. Now ptrdiff_t works for me, because it is defined as "typedef _W64 int ptrdiff_t;". Besides the warnings issue, "boost::detail::multi_array::index" should be a signed integer type, that satisfies the assertion "assert(sizeof(boost::detail::multi_array::index) == sizeof(std::size_t));". While this assertion will probably be satisfied on all current platforms, it is not garantied by the standard, which just reads: "The types are 'ptrdiff_t' which is the signed integer type of the result of substracting two pointers; 'size_t' which is the unsigned integer type of the result of the sizeof operator;". Thanks, Thomas

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extra semicolons
by Arkadiy Vertleyb 19 Jul '05

19 Jul '05

Hi all, Not having extra semicolons is one of the strongest arguments against incuding a trailing semicolon into a statement-generating macro. Can anybody explain why having an extra semicolon is considered a potential problem by some compilers? Isn't null as good as any other number? Shouldn't an empty statement be considered as good as any other statement? Regards, Arkadiy

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