- Boost - lists.boost.org

[mpl] The concept of laziness
by Cromwell Enage 26 Sep '05

26 Sep '05

I remember a thread that ran for a while on this topic, and I need to make sure I've wrapped my head around it correctly. Here are my takes on laziness: <take id="point-1"> A metafunction returns lazily if it can be used interchangeably with its return type. Numeric metatypes such as integral_c are examples of metafunctions that return lazily, e.g. "int_<6>" is the same as "typename int_<6>::type". Metafunctions such as next/prior, however, do not return lazily because they cannot be used interchangeably with their return types. For example, "times<next<int_<4> >,prior<long_<8> > >" is illegal; the expression must be "times<typename next<int_<4> >::type,typename prior<long_<8> >::type>". </take> <take id="point-2"> A metafunction evaluates a certain template argument lazily if it does not require the argument to be a fully instantiated type; otherwise, the evaluation is strict. The eval_if metafunction will strictly evaluate the second argument if the first argument is equivalent to false_; otherwise, it will strictly evaluate the third argument. </take> I'm less sure about point-2 than I am about point-1. In any case, feel free to correct any knowledge deficiencies I've exhibited, to make these definitions more complete. More examples would also be a great help. Cromwell D. Enage __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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bug report for bjam 3.1.11
by Lewis Hyatt 26 Sep '05

26 Sep '05

Hi All, I apologize if this has been reported before, but I couldn't find it after a long search. I encountered problems building bjam on a standard Linux distribution (uname -a: Linux 2.4.21-32.0.1.EL #1 Wed May 25 14:34:59 EDT 2005 i686 i686 i386 GNU/Linux) with gcc. (same problem with gcc 3.2.2 or 4.0.1). The executable seg faulted every time. I tracked it to the function var_defines() in variable.c which had a logic error at lines 124-130. I didn't investigate far enough to determine why the function was receiving strings consisting of a single quote, and I do not know if this is irregular or not, but in any case the attached patch (output from diff -c) corrects the issue. -Lewis *** boost-jam-3.1.11/variable.c 2005-05-29 23:42:38.000000000 -0400 --- variable.c 2005-09-25 22:27:31.000000000 -0400 *************** *** 121,127 **** # endif size_t len = strlen(val + 1); ! int quoted = val[1] == '"' && val[len] == '"'; if ( quoted && preprocess ) { --- 121,127 ---- # endif size_t len = strlen(val + 1); ! int quoted = val[1] == '"' && val[len] == '"' && len>1; if ( quoted && preprocess ) {

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Review Xpressive
by Tom Brinkman 26 Sep '05

26 Sep '05

*What is your evaluation of the design? Very good. * What is your evaluation of the implementation? Also, very good. * What is your evaluation of the documentation? I thought the documentation was comparable in quality to the best documented libraries in boost. * What is your evaluation of the potential usefulness of the library? As others have indicated, there is some overlap with other boost libraries. However, the emphasis of xpressive is different and somewhat more flexible. * Did you try to use the library? With what compiler? Did you have any problems? GCC 3.2. No problems. * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I've incorporated xpressive into a couple of small console applications. At first, I spent maybe 2 hours reading the documents and probably one hour to implement an xpressive solution. Since that time, I have read the documentation for an additional couple hours for more background. * Are you knowledgeable about the problem domain? Yes. As a user of boost::regex and boost::spirit. * Do you think the library should be accepted as a Boost library? Yes, without reservation. Tom Brinkman

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uncreatable
by Jason Hise 26 Sep '05

26 Sep '05

Why does the following compile? The parameter type of A's pure virtual function is private. How come B can see it, allowing it to override the pure virtual function? class A { private: struct S { }; virtual void bar ( S ) = 0; }; class B : public A { public: virtual void bar ( A::S ) { } }; int main ( ) { B b; return 0; } -Jason

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[mpl][math] double accuracy
by Peder Holt 25 Sep '05

25 Sep '05

What should we do about the accuracy of double_ operations? The implementation of plus,minus,times and divide mimics the behaviour of the runtime equivalent, double. This means that the mantissa is trunkated from 61 to 52 bit for every fundamental operation. The result of this, is that complex functions such as sine and exponential will differ from their runtime counterpart, unless a specialization is made for double_. The problem would disappear if we allow calculations with double_ to be more accurate than calculations with double. Is this a problem? Regards Peder

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[typeof] native support in intel and como
by Arkadiy Vertleyb 25 Sep '05

25 Sep '05

Can anybody familiar with these compilers explain what needs to be done in order to be able to use the "typeof" keyword with them? From looking on the web, I got the impression that they have to support it, but my attempts to setup the tests fail with "typeof" undefined (I tried __typeof__ before this). Thanks, Arkadiy

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[1.33.1][iostreams] Timetable and patches
by Jonathan Turkanis 25 Sep '05

25 Sep '05

Hi All, Do we have any timetable for 1.33.1? Will Bryant just pointed out a memory leak in Iostreams, and I'd like to post an Iostreams patch if 1.33.1 will not be ready reasonably soon. One more thing: before there was talk of 1.33.1, I prepared a patch for 1.33 to fix some minor stuff, but had trouble generating a single patch that worked for all the sourceforge 1.33 archives. Should it be necessary to post several patches, or was I doing something wrong? -- Jonathan Turkanis www.kangaroologic.com

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Boost regression notification (2005-09-25 [RC_1_33_0])
by Douglas Gregor 25 Sep '05

25 Sep '05

Boost regression test failures ------------------------------ Report time: 2005-09-25T15:24:07Z This report lists all regression test failures on release platforms. Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-RC_1_33_0/developer/i… 77 failures in 6 libraries: foreach (1) graph (5) iostreams (11) random (1) range (3) serialization (56) |foreach| rvalue_const: vc-7_1 |graph| betweenness_centrality_test: gcc-3.4.4-linux dag_longest_paths: gcc-3.4.4-linux dijkstra_cc: gcc-3.4.4-linux dijkstra_heap_performance: gcc-3.4.4-linux relaxed_heap_test: gcc-3.4.4-linux |iostreams| gzip_test: cw-9_5-darwin gcc-2.95.3-stlport-4.6.2-linux gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-3_3-darwin gcc-4.0.1-linux gcc-4_0-darwin intel-8.1-linux intel-9.0-linux vc-7_1 |random| random_test: gcc-3.3.6-linux |range| array: vc-6_5 vc-6_5-stlport vc-7_0 |serialization| test_contained_class_xml_archive: gcc-3.2.3-linux test_exported_binary_archive: vc-6_5 test_exported_binary_archive_dll: vc-6_5 test_exported_text_archive: vc-6_5 test_exported_text_archive_dll: vc-6_5 test_exported_text_warchive: vc-6_5 test_exported_text_warchive_dll: vc-6_5 test_exported_xml_archive: vc-6_5 test_exported_xml_archive_dll: vc-6_5 test_exported_xml_warchive: vc-6_5 test_exported_xml_warchive_dll: vc-6_5 test_no_rtti_binary_archive: vc-6_5 test_no_rtti_binary_archive_dll: vc-6_5 test_no_rtti_text_archive: vc-6_5 test_no_rtti_text_archive_dll: vc-6_5 test_no_rtti_text_warchive: vc-6_5 test_no_rtti_text_warchive_dll: vc-6_5 test_no_rtti_xml_archive: vc-6_5 test_no_rtti_xml_archive_dll: vc-6_5 test_no_rtti_xml_warchive: vc-6_5 test_no_rtti_xml_warchive_dll: vc-6_5 test_shared_ptr_132_binary_archive: vc-6_5 vc-6_5-stlport test_shared_ptr_132_binary_archive_dll: vc-6_5 test_shared_ptr_132_text_archive: vc-6_5 vc-6_5-stlport test_shared_ptr_132_text_archive_dll: vc-6_5 test_shared_ptr_132_text_warchive: vc-6_5 vc-6_5-stlport test_shared_ptr_132_text_warchive_dll: vc-6_5 test_shared_ptr_132_xml_archive: vc-6_5 vc-6_5-stlport test_shared_ptr_132_xml_archive_dll: vc-6_5 test_shared_ptr_132_xml_warchive: vc-6_5 vc-6_5-stlport test_shared_ptr_132_xml_warchive_dll: vc-6_5 test_shared_ptr_binary_archive: borland-5_6_4 vc-6_5 test_shared_ptr_binary_archive_dll: borland-5_6_4 vc-6_5 test_shared_ptr_text_archive: borland-5_6_4 vc-6_5 test_shared_ptr_text_archive_dll: borland-5_6_4 vc-6_5 test_shared_ptr_text_warchive: borland-5_6_4 vc-6_5 test_shared_ptr_text_warchive_dll: borland-5_6_4 vc-6_5 test_shared_ptr_xml_archive: borland-5_6_4 vc-6_5 test_shared_ptr_xml_archive_dll: borland-5_6_4 vc-6_5 test_shared_ptr_xml_warchive: borland-5_6_4 vc-6_5 test_shared_ptr_xml_warchive_dll: borland-5_6_4 vc-6_5

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Boost regression notification (2005-09-25 [HEAD])
by Douglas Gregor 25 Sep '05

25 Sep '05

Boost regression test failures ------------------------------ Report time: 2005-09-25T05:00:13Z 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. typeof Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… 176 failures in 14 libraries: concept_check (14) filesystem (8) foreach (7) graph (7) math (3) mpl (2) parameter (17) python (1) regex (1) serialization (40) spirit (2) thread (24) typeof (46) wave (4) |concept_check| stl_concept_covering: cw-9_4 gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin intel-win32-9_0 intel-win32-9_0 mingw-3_4_2 msvc vc-7_1 vc-7_1 |filesystem| convenience_test: msvc default_name_check_test: msvc fstream_test: msvc large_file_support_test: msvc operations_test: msvc operations_test_dll: msvc path_test: msvc path_test_dll: msvc |foreach| user_defined: cw-8_3 cw-9_4 cw-9_5-darwin msvc vc-6_5 vc-6_5-stlport vc-7_0 |graph| astar_search_test: vc-7_1 biconnected_components_test: vc-7_1 cuthill_mckee_ordering: vc-7_1 graphviz_test: vc-7_1 vc-7_1 vc-7_1 layout_test: intel-win32-9_0 |math| octonion_test: gcc-4_0-darwin quaternion_test: gcc-4_0-darwin special_functions_test: gcc-4_0-darwin |mpl| size_t: gcc-4_0-darwin gcc-4_0-darwin |parameter| basics: borland-5_6_4 gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux efficiency: gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux msvc macros: borland-5_6_4 gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux sfinae: borland-5_6_4 gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux msvc unnamed: borland-5_6_4 gcc-2.95.3-linux gcc-2.95.3-stlport-4.6.2-linux vc-7_1 |python| data_members: msvc |regex| static_mutex_test: msvc |serialization| test_class_info_load_binary_archive: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_binary_archive_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_archive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_archive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_warchive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_warchive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_archive: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_archive_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_warchive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_warchive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_const_save_fail1: msvc test_const_save_fail2: msvc test_const_save_fail3: msvc test_map_binary_archive_dll: msvc test_map_text_archive_dll: msvc test_map_text_warchive_dll: msvc |spirit| traverse_tests: intel-win32-9_0 traverse_tests_debug: intel-win32-9_0 |thread| test_barrier: msvc test_barrier_lib: intel-9.0-linux msvc test_condition: msvc test_condition_lib: intel-9.0-linux msvc test_mutex: msvc test_mutex_lib: intel-9.0-linux msvc test_once: msvc test_once_lib: intel-9.0-linux msvc test_read_write_mutex: msvc test_read_write_mutex_lib: intel-9.0-linux msvc test_thread: msvc test_thread_lib: intel-9.0-linux msvc test_tss: msvc test_tss_lib: intel-9.0-linux msvc test_xtime: msvc test_xtime_lib: intel-9.0-linux msvc |typeof| data_member_emulation: cw-9_4 data_member_native: intel-win32-9_0 intel-win32-9_0 function_emulation: cw-9_4 function_native: intel-win32-9_0 intel-win32-9_0 msvc function_ptr_emulation: cw-9_4 function_ptr_native: intel-win32-9_0 intel-win32-9_0 function_ref_emulation: cw-9_4 function_ref_native: intel-win32-9_0 intel-win32-9_0 lvalue_emulation: cw-9_4 lvalue_native: intel-win32-9_0 intel-win32-9_0 msvc member_function_emulation: cw-9_4 member_function_native: intel-win32-9_0 intel-win32-9_0 modifiers_emulation: cw-9_4 modifiers_native: cw-9_4 intel-win32-9_0 intel-win32-9_0 noncopyable_native: intel-win32-9_0 std_native: intel-win32-9_0 template_dependent_native: intel-win32-9_0 template_enum_native: intel-win32-9_0 template_int_emulation: cw-9_4 template_int_native: intel-win32-9_0 intel-win32-9_0 template_multiword_native: intel-win32-9_0 template_tpl_emulation: cw-9_4 template_tpl_native: intel-win32-9_0 intel-win32-9_0 msvc template_type_emulation: cw-9_4 template_type_native: intel-win32-9_0 intel-win32-9_0 type_emulation: cw-8_3 cw-9_4 cw-9_4 type_native: intel-win32-8_1 intel-win32-9_0 intel-win32-9_0 intel-win32-9_0 |wave| test_re2c_lexer: intel-9.0-linux test_slex_lexer: intel-9.0-linux testwave: gcc-3.3.6-linux intel-9.0-linux

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[serialization] Archive implementation
by Matthias Troyer 25 Sep '05

25 Sep '05

Hi Robert, After tracking down a linker error I realized that #include <boost/archive/impl/archive_pointer_oserializer.ipp> #include <boost/archive/impl/archive_pointer_iserializer.ipp> need to be included for all new archives that a user might develop, in order to allow serialization of pointers. Are there other such *.ipp files that an archive developer needs to watch out for? Matthias

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