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[proto] comments on documentation #1
by Markus Werle 15 Mar '08

15 Mar '08

Hi! This is a proposal for extra text which might have helped me to catch some things right from the beginning: Section "Accessing Children Nodes": Subsection "Expression Nodes as fusion sequnces" After "... arguments in order" please insert an improved version of the following paragraph (intended for first-contact-to-proto people like me) --- Note that in C++ operators are nothing else but special syntax for operations that can be written as function calls, e.g. a+b is equivalent to binary_plus(a, b). Proto "thinks" of operators in this way and - as introduced above - uses a type representation of the form expr<tag::binary_plus, typeA, typeB> This is why function calls are nothing special to proto and and are handled in analogy to operators: For function calls the type representation has a tag tag::function and the type of function is stored as extra template argument, so you obtain type representations of the form expr<tag::function, typeFunction, typeA, typeB> for a function call Function(A, B). So if a compile time algorithm in proto needs only access to the types of the arguments and not to the type of the function, the first argument has to be removed from the sequence. We will come back to this in a second: [Then show the example and then in the explanation add:] What happens during compilation with "fun(1, 2, 3, 4)"? The type of fun is in namespace proto, so it is "tainted" with Proto-ness exactly like _1 in the examples above. Similar to _1 + 2, which has a return type of expr<tag::binary_plus, ....> ;-) \footnote{Once in a time binary operator+ was tagged tag::plus, which led to trouble for the tag name of unary operator+. A lot of crazy proposals for the tag name were made, now we simply use tag::binary_plus and tag::unary_plus, no further discussions needed} ;-) the call fun(...) has a return type of expr<tag::function, PUT_SOME_CODE_HERE, ....> The integers are automatically wrapped in terminal<int>s. That's why proto is so cool. Since we are only interested in the arguments of the function call and already know that expression nodes are valid Fusion sequences and know that the first element in the fusion sequence is the function type, namely terminal<fun_t>::type alias expr<tag::terminal, bla bla>, we use a compile time algorithm which drops the first element from the list before pushing the result through other very useful algorithms of boost::fusion - in this example for_each and transform (Did we already mention that you are lost with proto if you do not know fusion?) ----------------------------- Markus

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[proto] docs: Calc2 improvement proposal
by Markus Werle 15 Mar '08

15 Mar '08

Hi! First of all: This is a very nice example. Fantastic idea to introduce index information stored in the terminals at this place in the docs - perfect. If you define arg as template<int I> struct arg {}; and change the code accordingly the reader is not in need to know anything about mpl::int_ and IMHO the code template <int I> double operator ()(proto::tag::terminal, arg<I>) const { return d[ I - 1 ]; } is easier to read than template<typename I> double operator ()(proto::tag::terminal, arg<I>) const { return d[ I() - 1 ]; } Note that this should be written for beginners like me, so one catches the idea immediately without taking the extra path to mpl here. Markus

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[filesystem] wpath_traits missing BOOST_FILESYSTEM_DECL
by Alexei Alexandrov 15 Mar '08

15 Mar '08

Hi, In Boost 1.34.1 the wpath_traits class misses BOOST_FILESYSTEM_DECL declaration and thus cannot be used with boost::filesystem is dynamically linked on Windows. Is this a bug or it's me who misses something? -- Alexei Alexandrov

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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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[filesystem] imbue for path_traits
by Alexei Alexandrov 15 Mar '08

15 Mar '08

Hi, Currently filesystem::path_traits doesn't have imbue() method while wpath_traits has. Thus, there is explicit assumption that external and internal encodings for path are the same. But this is not true sometimes. For example, currently it doesn't seem to be possible to use filesystem::path conveniently on Linux in cases when internal encoding of the application is UTF-8 while system encoding might differ from UTF-8 (GB2312, for example).

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[1.35][Property Tree] In or out for 1.35?
by John Maddock 15 Mar '08

15 Mar '08

Do we have a final decision on whether Property Tree is in Boost-1.35 or not? At present it's there in the SVN release branch, but without docs and no link from the main documentation index either :-( I guess my vote at this very late stage is to remove it from the release branch for 1.35, but leave it in Trunk? John.

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gcc-4.3 support
by Tim Blechmann 15 Mar '08

15 Mar '08

hi all, since gcc-4.3 has been released a short time ago, i'm curious about the plans for supporting it in boost 1.35 ... the ticket tracker does contain a few patches for gcc-4.3, which haven't been included in the trunk, yet ... http://svn.boost.org/trac/boost/query? status=new&status=assigned&status=reopened&summary=~4.3&order=priority any plans to include them before 1.35 is out? thnx, tim -- tim(a)klingt.org http://tim.klingt.org Cheat your landlord if you can and must, but do not try to shortchange the Muse. It cannot be done. You can't fake quality any more than you can fake a good meal. William S. Burroughs

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[Proto] review period extended to end March 28th
by Hartmut Kaiser 15 Mar '08

15 Mar '08

Hi all, There have been several requests to extend the Proto review period. For this reason the review now will end on March 28th. This should give you sufficient time to have a closer look at the library and to prepare a review. The original announcement follows: The review of Eric Nieblers Proto library starts today, March 1st 2008, and will end on March 14th. I really hope to see your vote and your participation in the discussions on the Boost mailing lists! --------------------------------------------------- About the library: Proto is a framework for building Domain Specific Embedded Languages in C++. It provides tools for constructing, type-checking, transforming and executing expression templates. More specifically, Proto provides: * An expression tree data structure. * Operator overloads for building the tree from an expression. * Utilities for defining the grammar to which an expression must conform. * An extensible mechanism for immediately executing an expression template. * An extensible set of tree transformations to apply to expression trees. * A mechanism for giving expressions additional behaviors and members. Documentation is here: http://boost-sandbox.sourceforge.net/libs/proto Download proto.zip from here: http://www.boost-consulting.com/vault/index.php?directory=Template%20Metapro gramming Proto is a very important infrastructure library, IHMO. It has been used as the backbone for several other library writing efforts already, such as Xpressive and the rewrite of Spirit (there it has been used for all three parts: the parser, the lexer and the generator modules), and it is a key enabling technology in the long-planned unification of Phoenix and the Lambda Library. --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - 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 Hartmut Review Manager

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Updating the Boost license information for 1.35?
by Rick Yorgason 15 Mar '08

15 Mar '08

Hey everyone, I've noticed a few things coming from this mailing list: * There's some rumblings about getting the 1.35 release out the door soon. * A list was compiled showing that uBLAS was the only Boost library that wasn't using the Boost Software License, or at least, the only one that couldn't be easily changed. <http://lists.boost.org/Archives/boost/2007/05/122130.php> * With little fanfare, permission was granted to release uBLAS under the BSL last September. <http://lists.boost.org/MailArchives/ublas/2007/09/2342.php> So, hey, this is great news! My question is, what do you think the chances are that 1.35 could be released under a blanket license? Since the only work required is changing some comments in some source files, it would be a shame if we had to wait another year and a half for this. Cheers, -Rick-

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1.35 ETA
by Richard Newman 14 Mar '08

14 Mar '08

I ask this not to badger well-intentioned volunteers, but to provoke constructive discussion. Version 1.34.1 was released on July 24, 2007, going on 8 months ago. Since that time 6 new libraries have been accepted with one more accepted provisionally (according to boost.org website). Prior to 1.34.1, 1.34.0 was released on May 12, 2007, 2-1/2 months prior. 1.34.0 was considered a very long release: it's predecessor (1.33.1) was released on Dec. 5, 2005, nearly 1-1/2 years prior. At one point, there was hope of getting 1.35.0 out before the end of 2007, given that it was to be a short release primarily to move to Trac and Subversion, without large functionality upgrades or code base improvements. As I recall, part of the intent was to move to faster release cycles with teams of release managers to reduce the imposition on any one volunteer. We are now nearing spring break, the beaches of Cancun beckon, and another round of messages about Google's Summer of Code have begun. Is there a realistic target date for releasing 1.35? Is there a distinct possibility that 1.35 will require a full year or more to close since it began? With respect, Richard Newman

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