October 2011 - Boost - lists.preview.boost.org

[1.48.0.beta 1][interprocess] detail namespace
by Jan Boehme 28 Oct '11

28 Oct '11

Hi, is the change of the name of the namespace 'detail' to 'ipcdetail' intended to be in the release? Isn't it over-qualified as it is located in the the namespace 'boost::interproces' anyway?. Btw it breaks our code and should mentioned in the release notes of the library. Thanks for reading, Jan.

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[filesystem and beyond] Narrow strings be UTF-8
by Yakov Galka 28 Oct '11

28 Oct '11

On Wed, Oct 26, 2011 at 22:13, Beman Dawes <bdawes(a)acm.org> wrote: > (2) V3 may work OK with the Microsoft 65001 UTF-8 codepage, although > I've never used it myself and you would have to pass in a UTF-8 > encoded narrow character name. > If it had been possible, it would simplify everything. Unfortunately, you cannot set UTF-8 codepage for windows API functions (you can for the console though). Microsoft isn't interested in making portability easier, so I don't see them adding the support in the nearest future. But they could. UTF-8 should be considered as the only default narrow encoding on windows, because all other ANSI encodings are not unicode-aware. On Wed, Oct 26, 2011 at 22:47, Beman Dawes <bdawes(a)acm.org> wrote: > On Wed, Oct 26, 2011 at 6:24 AM, Yakov Galka <ybungalobill(a)gmail.com> > wrote: > > [...] > > Even if you fix the Unicode problems, > > What Unicode problems are you running into? Although there are some > locale related tickets outstanding, I'm not aware of any Unicode > issues. > 1) The one that was brought up in the previous thread. 2) The complexity of writing portable unicode-aware code: currently you're forcing me to a) use wstring on windows, or if I prefer to use my favorite portable UTF-8 encoded strings b) write all the boilerplate code that passes codecvt everywhere as a parameter (see below why ¬imbue()). In both cases you're shifting the complexity to the higher-level code. It's not a kind thing for you as a low-level library developer to do, The library is expected to ℍ𝕚𝕕𝕖 the platform differences by providing a uniform interface. ⇒ Myth: Using the native encoding on each platform results in portable code. ‽ In some definition of 'portable' definitely yes. But not when things are shared among different platforms. It starts with files transferred between different systems and ends with the source code itself (there is a different between "" and L""). Uniformity == simplicity. Consider a simple case of loading a path from some project file and loading the referenced file: The project file is encoded in UTF-8 making it portable among all systems with CHAR_BIT == 8. // Option a) #include "codecvt_implementation.h" std::basic_ifstream<native_char> fin("project.file"); std::basic_string<native_char> str; fin.imbue(locale(fin.getloc(), new utf8_to_native_codecvt())); getline(fin, str); fs::ifstream fin2(project_path/str); // Option b) #include "codecvt_implementation.h" std::ifstream fin("project.file"); std::string str; getline(fin, str); fs::ifstream fin2(fs::path(project_path).append(str, utf8_to_native_codecvt())); // c) How it could be done std::ifstream fin("project.file"); std::string str; getline(fin, str); fs::ifstream fin2(project_path/str); ⇒ Use boost⸬filesystem⸬imbue to convert b to c. ‽ Who is responsible for calling imbue()? I'm writing library code. I'm not allowed to change the global-state. ⇒ This code will break: int main(int argc, char* argv[]) { fs::ifstream fin(argv[1]); } ‽ It works fine for ASCII characters on all sane platform. For non-ASCII, I don't care. It's already not unicode-aware if the native encoding is not UTF-8 (which can't be so on Windows). If the writer of this code really cares about internationalization, she can use boost⸬program_options (assuming it's also changed to follow the UTF-8 convention). Otherwise she's a hypocrite. ⇒ UTF-8 is slow. ‽ Compared to what? You haven't measured this. On windows: we must do complicated operations on paths before we pass them to the OS anyway (system_complete, prepend \\?\). Most of the strings contain ASCII characters so std::strings take less memory, thus decreasing cache thrashing in other parts of the program. On other OSes: the encoding is already almost always UTF-8. Experience shows that the small overhead (if it's an overhead at all) is not the bottleneck. Many cross-platform libraries already switched to UTF-8 for narrow-chars (see one of the previous discussion for a list), and I don't see a reason why boost can't be the next. -- Yakov

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Making Boost.Filesystem work with GENERAL filenames with g++ in Windows (a solution)
by Alf P. Steinbach 28 Oct '11

28 Oct '11

First, apologies if I'm posting to the wrong group/list; if so then please redirect me. IMHO access to files is a crucial part of Boost.Filesystem. However, with Boost 1.47, and using g++ 4.4.1 in Windows 7, boost::filesystem::ifstream etc. fail to open or create files with non-ANSI characters. It works fine with Visual C++; it FAILS with g++ 4.4.1, which is the one bundled with the Code::Blocks IDE. The failure probably has nothing to do with the g++ version: it's due to g++ not offering the Visual C++ wchar_t oriented extensions to the standard iostreams (Boost.Filesystem uses these Visual C++ extensions). I stumbled onto this while I was writing about using Unicode in C++ programming in Windows. I wrote up a technical solution in section 5, starting on page 16, of that work-in-progress document, available on Google Docs at: https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B2oiI2re… Essentially, the fix I ended up with, full source code given in the above doc, uses Windows short file names if (1) there is no wide character support and if furthermore (2) the filename can't be perfectly translated to ANSI. The C++ implementation's support for wide chars is automatically detected using C++98-compatible code. I do not know what to do with this. But considering that Boost.Filesystem is slated for later inclusion in the C++ standard library (or at least into TR2), I think it would be nice if it is able to give access to all accessible files in Windows, also with g++, so that we don't end up with a file handling part of the standard library that can't handle files in general; hence this posting and plea for advice -- what more should I do, if anything? Cheers, - Alf

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Re: [boost] [1.48.0] Beta 1 is now available from SourceForge
by Martin Elzen 28 Oct '11

28 Oct '11

Okay, I gave compiling the beta 1 another shot, as follows: ./bootstrap.sh --prefix=/home/martin/app/boost/installation --with-icu=/home/martin/app/icu/installation ./b2 -sICU_PATH=/home/martin/app/icu/installation install >out.b2.install 2>&1 & the b2 output then does start as follows: Performing configuration checks - has_icu builds : yes warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - iconv (libc) : yes - icu : yes ... but then later on there are compilation errors in Boost.Locale, such as: > In file included from libs/locale/src/icu/formatter.cpp:25:0: > libs/locale/src/icu/predefined_formatters.hpp: In member function ‘icu_48::NumberFormat* boost::locale::impl_icu::icu_formatters_cache::number_format(boost::locale::impl_icu::icu_formatters_cache::fmt_type) const’: > libs/locale/src/icu/predefined_formatters.hpp:127:61: error: ‘URBNF_SPELLOUT’ was not declared in this scope > libs/locale/src/icu/predefined_formatters.hpp:127:61: note: suggested alternative: > /home/martin/app/icu/installation/include/unicode/rbnf.h:49:5: note: ‘icu_48::URBNF_SPELLOUT’ > libs/locale/src/icu/predefined_formatters.hpp:130:61: error: ‘URBNF_ORDINAL’ was not declared in this scope > libs/locale/src/icu/predefined_formatters.hpp:130:61: note: suggested alternative: > /home/martin/app/icu/installation/include/unicode/rbnf.h:50:5: note: ‘icu_48::URBNF_ORDINAL’ > > "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_LOCALE_DYN_LINK=1 -DBOOST_LOCALE_NO_WINAPI_BACKEND=1 -DBOOST_LOCALE_WITH_ICONV=1 -DBOOST_LOCALE_WITH_ICU=1 -DBOOST_THREAD_NO_LIB=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -DNDEBUG -I"." -I"/home/martin/app/icu/installation/include" -c -o "bin.v2/libs/locale/build/gcc-4.6.1/release/threading-multi/icu/formatter.o" "libs/locale/src/icu/formatter.cpp" The above errors are probably caused because I did what ICU recommends you do (for the first time ever), which is: -# define U_USING_ICU_NAMESPACE 1 + // Set to 0 to force namespace declarations in ICU usage. +# define U_USING_ICU_NAMESPACE 0in the ICU unicode/uversion.h file The above is advised in ICU 's readme.html in the How To Build And Install ICU / Recommended Build Options section... Has that advice become incorrect in recent ICU versions, perhaps?

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[1.48.0] Beta 1 is now available from SourceForge
by Beman Dawes 27 Oct '11

27 Oct '11

Boost release 1.48.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/boost/1.48.0.beta.1/ This release includes 3 new libraries (Container, Locale and Move), an extension to TypeTraits to support operator detection as well as updates to many existing libraries. For partial details of what's in the release, see http://beta.boost.org/users/history/version_1_48_0.html. This page is still in process of being updated, and there are some known issues with links. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus

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[1.48.0] Beta 1 release candidates available
by Martin Elzen 27 Oct '11

27 Oct '11

Beman Dawes <bdawes(a)acm.org> wrote: > Release candidate files for 1.48.0 beta 1 are available at > http://boost.cowic.de/rc/ > > As always, the release managers would appreciate it if you download > the candidate of your choice and give building it a try. Please report > both success and failure, and anything else that is noteworthy. On Ubuntu 11.10 amd64 with g++ (and gcc) 4.6.1, I built ICU 4.8.1 with almost all default options except for specifying a non-default installation dir. Then I created the LD_LIBRARY_PATH environment variable and set it to the lib dir of that new ICU installation *but did not* also create an ICU_PATH environment variable. Then I ran the boost bootstrap.sh script with a '--with-icu=/home/martin/app/icu/installation' parameter. The output of the b2 contained (among other things) the following bits about ICU: - has_icu builds : yes ... - icu : no - icu (lib64) : no Which led me to expect that the boost regex libs would end up referencing the Ubuntu default ICU libs (which was not what I wanted to do). But they didn't, instead they *did* correctly reference the newly built ICU libraries (or at least that's how I'm interpreting the output of ldd against libboost_regex.so ). Which is nice, but doesn't that also mean that the docs in Boost regex about the ICU_PATH environment variable might need some revision? Or did I just luck out somehow?

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[interprocess] native Windows cond_var + mutex
by Dan Brown 27 Oct '11

27 Oct '11

Informed the previous patch was removed. Attaching patch without .zip.

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[parameter] non-type template params
by lcaminiti 26 Oct '11

26 Oct '11

Hello all, Does Boost.Parameter support named parameters for non-type template parameters? For example, can I use Boost.Parameter on all the template parameters below including default_value? template< typename Value, Value default_value = Value() > class none { ... }; >From the docs, it seems that this is not possible but I might be missing something: http://www.boost.org/doc/libs/1_47_0/libs/parameter/doc/html/index.html#par… Thanks a lot. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-parameter-non-type-template-params… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[atomics] Short review
by Phil Endecott 26 Oct '11

26 Oct '11

Dear All, Apologies for not having time to write a proper review for this important library. However, I have previously looked at this code in some depth, and I am using it in a number of shipping products. Based on that, I am reasonably confident that it is useful and functional. As others have said, the documentation needs some attention. In particular, I missed information about supported platforms and types. Users can reasonably ask whether a particular type is supported natively or whether a fallback is used, and what the fallback is. A link to the std::atomic spec (or a freely-downloadable draft of it) would also be useful. I believe that this is a vitally important and long-overdue library that should be accepted without delay. Regards, Phil.

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Re: [boost] [interprocess] submission
by Stewart, Robert 25 Oct '11

25 Oct '11

Dan Brown wrote: > Christian Holmquist wrote: > > > > I have a question about submissions. I have an > > > enhancement, not a fix, for boost::interprocess (win32 > > > native mutex and condition variables as an alternative to > > > emulation). Ok to just submit the zip or should I open a > > > ticket first? > > > > see: > > http://www.boost.org/community/policy.html#effective > > > > i.e., include [Interprocess] in the email topic so maybe the > > maintainer will read it. > > Helpful, thank you. Another question. Not only is it helpful, it just might get you a useful answer to your query, which I'll leave to Ion. Consequently, I added it for you. > I may not be able to justify to my employer completing the work > to the satisfaction of all tests. For example, I don't have a > working win32 native implementation of sharable and sharable- > upgradable mutexes (aka read-write locks, I believe). Is it > worth submitting in such a state in hopes others might be able > to contribute, or should I hold off until I have time implement > these and get all tests working? I suspect the answer will be that offering something, even if not everything, will be helpful. Nevertheless, you need Ion to respond. _____ Rob Stewart robert.stewart(a)sig.com Software Engineer using std::disclaimer; Dev Tools & Components Susquehanna International Group, LLP http://www.sig.com ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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