December 2007 - Boost - lists.boost.org

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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Proposed addition to the iterator library for iterating over all tuples.
by Alex Mendes da Costa 19 Jun '09

19 Jun '09

Hi folks: I quite often have to write code to do the following: Given N sequences, generate all the N-tuples s.t. the i'th element in each tuple is drawn from the i'th sequence. For example, if sequence S1 is { 1, 2, 3 } and sequence S2 is { 10, 20 }, I need to generate these tuples: (1, 10), (2, 10), (1, 20), (2, 20). I think this problem could be solved elegantly with a iterator similar to zip_iterator. I have some questions: (1) Is there already a way to do this in boost? (2) If not, would this be a worthwhile addition to the iterator library? (3) If so, could I contribute code for this, or must the existing library owners write it? (4) If so, how would I go about getting my code added? Most of the docs seem to be about submitting entire libraries, rather than extensions to existing libraries. Thanks, Alex

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[asio]: extending asio
by Andreas Pokorny 17 Aug '08

17 Aug '08

Hello, I would like to add more asynchronous event sources to asio, like: - input events for mouse, keyboard and joystick .. - window exposure, move, resize events in some generic form, - generic "quit" events - file alteration With directFB/X11/Unix/Linux most of that can be done directly through select or epoll. But since reading the message and parsing events is mostly done by a third party library, I would only need the reactor part for these. Is this possible with asio? According to msdn it seems to be possible to create so called event objects for direct input devices. I am no win32 expert so I do not know if one can combine that with completion ports? Regards Andreas Pokorny

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Mac OS universal builds: testers needed
by Mat Marcus 25 Jul '08

25 Jul '08

I've made a number of changes to my universal-binary supporting darwin.jam patch (shipping with the Adobe Source Library) in order to address the concerns raised by Rene and others at http://svn.boost.org/trac/boost/ticket/989 : My current version supports invocations like: bjam architecture={combined,x86,power} link={shared,static} address-model={64,32} That is, universal builds are now supported, along with 64 bit builds. I'd like to ask for the help from a few volunteers who'd be willing to test it out, before I submit my patch for consideration. Anyone interested in helping me test it? If so, please contact me off list and I'll send you a couple of boost build files to replace. I still have a bit of cleanup to do. Specifically, on the mac, if a build doesn't specify an -arch parameter, the architecture (and perhaps the address model) of the host machine is used. I'm not really comfortable with the same folder path meaning different things on different machines. So, I plan to do something like the following in darwin.jam (in invented pseudo code) SWITCH(on result of /usr/bin/arch) { # host machine's architecture CASE(ppc) use <architecture>power/<address-model>32 as the default CASE(i386) use <architecture>x86/<address-model>32 as the default CASE(ppc64) use <architecture>power/<address-model>64 as the default CASE(x86_64) use <architecture>x86/<address-model>64 as the default DEFAULT error, unknown arch Thanks, Mat

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[dynamic_bitset] bug in to_ulong() in dynamic_bitset.hpp
by Boris Gubenko 05 Jul '08

05 Jul '08

A failure of dynamic_bitset library test dyn_bitset_unit_tests3 on Tru64/cxx and HP-UX/aCC revealed what appears to be a bug in <boost/dynamic_bitset/dynamic_bitset.hpp> introduced after Boost 1.34. The bug affects platforms where 'long' type is larger than 'int'. On both Tru64 and HP-UX, 'int' is a 32-bit type. On Tru64, 'long' is a 64-bit type. On HP-UX, 'long' is a 64-bit type in 64-bit data model (+DD64, which is how Boost testing is done on this platform) and 32-bit type otherwise. The test also fails on other platforms and while I cannot verify it, from the test output it apears that these platforms are affected by the same bug. What fails is the two testcases below in b.to_long() suite in boost/libs/dynamic_bitset/dyn_bitset_unit_tests3.cpp invoked with run_test_cases<unsigned int>() : { std::string str(ul_width - 1, '1'); boost::dynamic_bitset<Block> b(str); Tests::to_ulong(b); } { std::string ul_str(ul_width, '1'); boost::dynamic_bitset<Block> b(ul_str); Tests::to_ulong(b); } The code in <boost/libs/dynamic_bitset/bitset_test.hpp> converts dynamic_bitset<unsigned int> argument to unsigned long and checks that the appropriate bits in the result are set: result_type num = lhs.to_ulong(); // Be sure the number is right if (sz == 0) BOOST_CHECK(num == 0); else { for (std::size_t i = 0; i < sz; ++i) BOOST_CHECK(lhs[i] == (i < n ? nth_bit(num, i) : 0)); } This check fails for the bits in the upper half of the result. Here is an excerpt from dynamic_bitset<Block, Allocator>::to_ulong() function in <boost/dynamic_bitset/dynamic_bitset.hpp> in the trunk: result_type result = 0; for (size_type i = 0; i <= last_block; ++i) { assert((size_type)bits_per_block * i < (size_type)ulong_width); result |= (m_bits[i] << (bits_per_block * i)); } In our case, last_block = 1 and bits_per_block = 32. m_bits[i] has 'unsigned int' type. On the second loop iteration, a 32-bit integer is left-shifted by 32 bit positions. This triggers undefined behaviour. From 5.8 - Shift operators [expr.shift] : "The behavior is undefined if the right operand is [...] greater than or equal to the length in bits of the promoted left operand." With cxx and aCC, such shift results in zeroing of all bits of the left operand. Here is the code from <boost/dynamic_bitset/dynamic_bitset.hpp> in Boost 1.34 : unsigned long result = 0; for (size_type i = 0; i <= last_block; ++i) { assert((size_type)bits_per_block * i < (size_type)ulong_width); // gps unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); } Here on the second loop iteration, a 64-bit long is left-shifted by 32 bit positions which yields the intended result. x.cpp below illustrates the difference between trunk and Boost 1.34: x.cpp ----- #include <stdio.h> #include <limits.h> int main() { unsigned int m_bits[] = { UINT_MAX, UINT_MAX }; unsigned int bits_per_block = sizeof(int) * CHAR_BIT; unsigned long result = 0; for(int i = 0; i <= 1 ; ++i) { #ifndef Boost_1_34 result |= (m_bits[i] << (bits_per_block * i)); #else unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); #endif printf("result = %llx\n", result); } } cxxosf.zko.hp.com> cxx x.cpp && a.out result = ffffffff result = ffffffff cxxosf.zko.hp.com> cxx x.cpp -DBoost_1_34 && a.out result = ffffffff result = ffffffffffffffff cxxosf.zko.hp.com> Replacing result |= (m_bits[i] << (bits_per_block * i)); with unsigned long piece = m_bits[i]; result |= (piece << (bits_per_block * i)); on the trunk makes the test succeed: verified on Tru64/cxx and on HP-UX/aCC. In <http://lists.boost.org/Archives/boost/2007/12/131126.php> I said: > It looks like a regression in boost/dynamic_bitset/dynamic_bitset.hpp > introduced in 1.35, but even in 1.34.1, it seems to me that the code in > to_ulong() is relying on undefined behaviour. What I was referring to is the code in 1.34 applying bitwise shift operator to a long operand. It would trigger an undefined behavior in C where "The operands shall have integer type", but it is legal in C++ where "The operands shall be of integral or enumeration type". So, I no longer claim that the code in 1.34 is relying on undefined behaviour. And the last thing: why the bug affects only platforms where 'long' type is larger than 'int'? Because if they are the same, as is the case on VMS or HP-UX in 32-bit data model, last_block = 0 and the single iteration of the for loop just assigns m_bits[0] to the result: the right operand of the shift operator is zero. To fix the problem, I suggest to replace the buggy code in <boost/dynamic_bitset/dynamic_bitset.hpp> in the trunk with that in 1.34. If there are no objections, I can do it. Thanks, Boris

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libs/dynamic_bitset/bitset_test unmerged changes?
by David Abrahams 05 Jul '08

05 Jul '08

Should these be in the trunk? Index: bitset_test.hpp =================================================================== --- bitset_test.hpp (revision 40672) +++ bitset_test.hpp (working copy) @@ -1006,7 +1006,8 @@ bool did_throw = false; try { - s << b; + static_cast<void> + (s << b); } #if defined BOOST_OLD_IOSTREAMS catch(...) { @@ -1081,7 +1082,8 @@ const std::ios::iostate except = is.exceptions(); bool has_stream_exceptions = true; try { - is >> b; + static_cast<void> + (is >> b); } catch(const std::ios::failure &) { did_throw = true; -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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[boost] [boost][gacap]Is any interesting to "Generating All Combinations and Permutations"？
by Ben Bear 19 May '08

19 May '08

Hi, all `gacap' is template library of "Generating All Combinations and Permutations". It's supper of std::next_permutation() and std::prev_permutation(). There's a old discussion: "[boost] [tr2]Add Combination against std::permutation. HELP!" http://lists.boost.org/Archives/boost/2006/09/110176.php I register a project in sf.net, http://gacap.wiki.sourceforge.net/. Some introductions are here. I put a .zip file in the vault, vault/Algorithms/gacap-0.0.4.zip. http://boost-consulting.com/vault/ It can also be downloaded from http://sourceforge.net/project/showfiles.php?group_id=209093 The package contains: gacap's header files doc/ example/ test/ doc/gacap.txt and doc/classes.txt are important introductions. I test it under three compilers, see doc/compile.txt. It's one year later. Thanks.

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filesystem::wpath and Linux
by Johan Ström 15 Mar '08

15 Mar '08

Hello list! Im working on an app wich is to run on windows, linux and OSX. I just switched from using filesystem::path to wpath, to be able to use i18n'ed paths on Windows. However this gave me a bunch of problems on Linux. A simple test case: test.cpp #include <iostream> #include <boost/filesystem/path.hpp> #include <boost/filesystem/convenience.hpp> namespace fs = boost::filesystem; int main() { fs::wpath mypath(L"/tmp/some/Directories"); for(int i = 0; i < 10; i++) { try { std::wcout << "Creating " << mypath << " nr " << i; fs::create_directories(mypath); }catch(std::exception&e) { std::cout << e.what() <<std::endl; } } } And Jamfile: import modules ; BOOST_ROOT = [ modules.peek : BOOST_ROOT ] ; use-project /boost : $(BOOST_ROOT) ; project wpathtest : requirements <library>/boost/filesystem//boost_filesystem/<link>static ; exe test : test.cpp : ; Running this in GDB on Linux with gcc 4.1.1, boost 1.34.1 (.0 too): (gdb) % dev1 ~/testcase$ gdb ./bin/gcc-4.1.1/debug/test GNU gdb Red Hat Linux (6.3.0.0-1.143.el4rh) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux-gnu"...Using host libthread_db library "/lib/tls/libthread_db.so.1". (gdb) run Starting program: /home/johan/testcase/bin/gcc-4.1.1/debug/test Creating /tmp/some/Directories nr 0 *** glibc detected *** double free or corruption (out): 0x0891e858 *** Program received signal SIGABRT, Aborted. 0x001cf7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2 (gdb) where #0 0x001cf7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2 #1 0x002107a5 in raise () from /lib/tls/libc.so.6 #2 0x00212209 in abort () from /lib/tls/libc.so.6 #3 0x00244a1a in __libc_message () from /lib/tls/libc.so.6 #4 0x0024b2bf in _int_free () from /lib/tls/libc.so.6 #5 0x0024b63a in free () from /lib/tls/libc.so.6 #6 0x00654041 in operator delete () from /usr/lib/libstdc++.so.6 #7 0x0065408d in operator delete[] () from /usr/lib/libstdc++.so.6 #8 0x0804e233 in boost::checked_array_delete<char> (x=0x891e858 "\200 \200\200\200\200��\200\200\200\200�\200\200\200\200�\200\200 \200\200p") at /home/common/boost_1_34_1/boost/checked_delete.hpp:41 #9 0x0804e249 in ~scoped_array (this=0xbfefada0) at /home/common/ boost_1_34_1/boost/scoped_array.hpp:65 #10 0x0804f983 in boost::filesystem::wpath_traits::to_external (ph=@0xbfefaf1c, src=@0xbfefadfc) at /home/common/boost_1_34_1/libs/ filesystem/src/path.cpp:96 #11 0x0804af53 in boost::filesystem::basic_path<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits>::external_file_string (this=0xbfefaf1c) at /home/common/boost_1_34_0/boost/filesystem/ path.hpp:302 #12 0x0804b917 in boost::filesystem::exists<boost::filesystem::basic_path<std::basic_strin g<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfefaf1c) at /home/common/ boost_1_34_0/boost/filesystem/operations.hpp:279 #13 0x0804ba6d in boost::filesystem::exists (ph=@0xbfefaf1c) at /home/ common/boost_1_34_0/boost/filesystem/operations.hpp:601 #14 0x0804c06d in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfefaf1c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:42 #15 0x0804c219 in boost::filesystem::create_directories (ph=@0xbfefaf1c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #16 0x0804c1b3 in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfefaf7c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:51 #17 0x0804c219 in boost::filesystem::create_directories (ph=@0xbfefaf7c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #18 0x0804c1b3 in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfefafc0) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:51 #19 0x0804c219 in boost::filesystem::create_directories (ph=@0xbfefafc0) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #20 0x0804a4c0 in main () at test.cpp:14 (gdb) If I instead remove the for/try stuff (only keep fs::wpath and fs::create_directories(mypath) and the std::wcout, I get this: (gdb) run Starting program: /home/johan/testcase/bin/gcc-4.1.1/debug/test Creating /tmp/some/Directories nr terminate called after throwing an instance of 'boost::filesystem::basic_filesystem_error<boost::filesystem::basic_path <std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> >' what(): boost::filesystem::wpath::to_external conversion error Program received signal SIGABRT, Aborted. 0x001cf7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2 (gdb) where #0 0x001cf7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2 #1 0x002107a5 in raise () from /lib/tls/libc.so.6 #2 0x00212209 in abort () from /lib/tls/libc.so.6 #3 0x006571bb in __gnu_cxx::__verbose_terminate_handler () from /usr/ lib/libstdc++.so.6 #4 0x00654ed1 in __cxa_call_unexpected () from /usr/lib/libstdc++.so.6 #5 0x00654f06 in std::terminate () from /usr/lib/libstdc++.so.6 #6 0x0065504f in __cxa_throw () from /usr/lib/libstdc++.so.6 #7 0x0804b69c in boost::throw_exception<boost::filesystem::basic_filesystem_error<boost:: filesystem::basic_path<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > > (e=@0xbfeed054) at /home/common/ boost_1_34_0/boost/throw_exception.hpp:39 #8 0x0804f669 in boost::filesystem::wpath_traits::to_external (ph=@0xbfeed1cc, src=@0xbfeed0ac) at /home/common/boost_1_34_0/libs/ filesystem/src/path.cpp:94 #9 0x0804ad15 in boost::filesystem::basic_path<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits>::external_file_string (this=0xbfeed1cc) at /home/common/boost_1_34_0/boost/filesystem/ path.hpp:302 #10 0x0804b6d9 in boost::filesystem::exists<boost::filesystem::basic_path<std::basic_strin g<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfeed1cc) at /home/common/ boost_1_34_0/boost/filesystem/operations.hpp:279 #11 0x0804b82f in boost::filesystem::exists (ph=@0xbfeed1cc) at /home/ common/boost_1_34_0/boost/filesystem/operations.hpp:601 #12 0x0804be2f in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfeed1cc) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:42 #13 0x0804bfdb in boost::filesystem::create_directories (ph=@0xbfeed1cc) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #14 0x0804bf75 in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfeed22c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:51 #15 0x0804bfdb in boost::filesystem::create_directories (ph=@0xbfeed22c) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #16 0x0804bf75 in boost::filesystem::create_directories<boost::filesystem::basic_path<std: :basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::filesystem::wpath_traits> > (ph=@0xbfeed278) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:51 #17 0x0804bfdb in boost::filesystem::create_directories (ph=@0xbfeed278) at /home/common/boost_1_34_0/boost/filesystem/ convenience.hpp:88 #18 0x0804a2f3 in main () at test.cpp:10 The double-delete doesnt look too good, does it? The other problem, this makes wpath pretty useless in crossplatform if it cannot decode itself? Even when its such a simple path.. I've done some googling on wpath but there doesnt seem to be very much usage of it.. Any clues? Thanks! -- Johan Ström Stromnet johan(a)stromnet.se http://www.stromnet.se/

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Review Request:boost.lexer
by Ben Hanson 01 Feb '08

01 Feb '08

Hi There, I have posted boost.lexer to the Boost File Vault and would like to request a review. Hartmut has integrated my library 'lexertl' into Spirit already, so this is the boost version of that library. Thanks, Ben Hanson

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[rfc] I/O Chain Library, Preview Release
by Sebastian Redl 01 Feb '08

01 Feb '08

Hi, Back in June I posted some thoughts about what I'd expect from a properly done I/O library.[1] Based on the ensuing discussion I then designed such a library. Over the last months, I've worked hard at implementing the thing. It is with quite a bit of pride, then, that I announce the IOChain preview release 1. You can get the source here: http://stud3.tuwien.ac.at/~e0226430/iochain-preview-1.tar.bz2 There are currently some assumptions in the build files that require a tiny bit of setup. 1) Unpack the source into some directory. 2) Grab the latest Boost trunk. 3) In the unpacked source, make a symlink to the Boost trunk called "realboost". E.g. tar -xjf iochain-preview-1.tar.bz2 cd iochain ln -s /path/to/boost/trunk realboost 4) Add zlib to your user config. If you have zlib where it is easily found, this is as easy as adding this line to ${HOME}/user-config.jam: lib zlib : : <name>z ; I'm sorry for the inconvenience. Documentation is in quickbook format. A generated version is available here: http://stud3.tuwien.ac.at/~e0226430/iochain/ This is a preview release. Its only purpose is to get comments. It has not seen widespread compiler testing yet (only GCC 4.1 on a 64-bit Linux). Features implemented so far: - The infrastructure. - File I/O (POSIX only - a Win32 implementation exists, but hasn't seen a compiler yet, so don't expect it to compile, much less work) - In-memory I/O (fixed buffers and std::vector). - Read-ahead and write-collect buffers (like buffering in the current streams). - Various tools to support backtracking. - Combining bytes into larger types. (Only naive methods currently.) - On-the-fly CRC calculation. - On-the-fly zlib compression. The ultimate goal of the library is to completely replace iostreams. All discussion, suggestions, and criticisms are welcome. Sebastian Redl [1] http://lists.boost.org/Archives/boost/2007/06/123478.php

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