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Re: [boost] [filesystem] wfstream file open does not create file in
by Ramakrishna, Kirankumar IN BLR SISL 22 Jun '10

22 Jun '10

Hi, I upgraded to boost version 1.43, but that did not help. Still file creation fails with wfstream and error code set is ERROR_FILE_NOT_FOUND. Below code captures the error codes #include "boost/filesystem/fstream.hpp" int main() { boost::filesystem::path pA("C:\\testA.txt"); boost::filesystem::wpath pW(L"C:\\testW.txt"); boost::filesystem::fstream fileHandleA; boost::filesystem::wfstream fileHandleW; fileHandleA.open(pA, std::ios_base::out); cout << "fileHandleA.fail() return value is: " << fileHandleA.fail() << endl; cout << "Error code is: " << GetLastError() << endl; fileHandleW.open(pW, std::ios_base::out); cout << "fileHandleW.fail() return value is: " << fileHandleW.fail() << endl; cout << "Error code is: " << GetLastError() << endl; return 0; } Am I doing something wrong? Regards, Kiran On 2010-06-19 00:44, Beman Dawes wrote: > On Thu, Jun 17, 2010 at 9:48 AM, Ramakrishna, Kirankumar IN BLR SISL > <Kiran.Ramakrishna@???> wrote: > > Hello, > > > > I am using boost version 1.42 and the below code is tested on Windows Xp SP3 and Suse 11.2 > > > > The below code creates new file when opened using fstream object, but fails to create when opened using wftream object. > > This behavior is consistent across platforms (Windows and Linux). > > Also the error code which I get after fileHandleW.open call is, > > > > > > Â 1. Â ERROR_FILE_NOT_FOUND for Â std::ios_base::out > > Â 2. Â ERROR_NEGATIVE_SEEK for std::ios_base::app > > > > In case of append mode, the file gets created. But still I get the above mentioned error code. > > > > Important notice: This e-mail and any attachment there to contains corporate proprietary information. If you have received it by mistake, please notify us immediately by reply e-mail and delete this e-mail and its attachments from your system. Thank You.

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[website] Smaller favicon.ico file
by Jeremiah Willcock 21 Jun '10

21 Jun '10

Our current favicon.ico file (on www.boost.org) is very large (22k), and includes several icons that are too large for the standard 16x16 size for a favicon. Looking at some directions for compressing them, I have created the attached icon which is only 318 bytes and looks almost as good as the current icon. It might be worthwhile to consider replacing the current favicon with this file. It is also available as https://svn.boost.org/htdocs/site/favicon.ico (the favicon for svn.boost.org, but your browser is unlikely to use the new icon if you've downloaded the old one); Dong Inn and I put that in last week as part of some other performance optimizations in Trac. Purging old favicons from Firefox's cache is difficult, though, so you may just want to download it directly and view it in an image viewer. -- Jeremiah Willcock

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Library design Q : overloads v/s default args
by Roshan 21 Jun '10

21 Jun '10

Hope this is not a silly question. The C++ Standard library does not use default arguments. Instead it provides an additional overload. Anybody know why ? For e.g. It provides the following two overloads for accumulate : template<class Itr, class T> accumulate(Itr first, Itr last, T init); template<class Itr, class T, class BinOp> accumulate(Itr first, Itr last, T init, BinOp op); instead of: template<class Itr, class T, class BinOp> accumulate(Itr first, Itr last, T init, BinOp op = std::plus<T>() ); I am wondering if there is any reason to avoid default arguments in general purpose libraries ? - Roshan

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[uuid] Dependency on Boost.MPL & Boost.TypeTraits
by Kedar Bodas 21 Jun '10

21 Jun '10

Hello, The <boost/uuid/uuid.hpp> header currently has a dependency on <boost/mpl/bool.hpp> & <boost/type_traits/is_pod.hpp>. This is only used to declare the type_trait is_pod<uuids::uuid> AFAICT for the uuid_serialize.hpp header. No other part of the library seems to have any dependency on it. Here's my problem: By company policy I am not allowed to make any changes to a boost library header. The MPL & type_traits libraries are not currently authorized for use within our code. This means I can't use Boost.Uuid either. Is it possible for the above included headers to be enclosed within an inclusion guard like UUID_NO_TYPE_TRAITS_DEPENDENCY so that by defining this macro I can remove this dependency without having to change the <boost/uuid/uuid.hpp> header? Or better still since only uuid_serialize.hpp seems to need it this dependency might be moved there. Since we don't use Boost.Serialization in our code this will solve my problem. This will also serve the purpose of reducing the dependencies of the core part of the library and make it more modular. PS. I am not really sure if this belongs in this list or the boost-users mailing list. Thanks, -- Kedar Bodas, Think3 Designs Pvt. Ltd.

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[trac] spam
by Steven Watanabe 21 Jun '10

21 Jun '10

AMDG ticket https://svn.boost.org/trac/boost/ticket/1556 just got spammed, and I notice that it has a bunch of earlier spam too. In Christ, Steven Watanabe

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[boost[program options] locale support
by Christoph Heindl 21 Jun '10

21 Jun '10

hi, from the documentation [1] : "[...] the library uses the codecvt<wchar_t, char> locale facet from the global locale." The quote is taken from the unicode-documentation part. May i ask why the locale is taken from the global locale, instead of the locale assigned to the stream? What I'd like to do is (currently yields a logic_error) // assume stream contains "a = 1,2" // ... std::locale loc("German_Germany"); stream.imbue(loc); po::parse_config_file(stream, opts, false); instead i have to std::locale loc("German_Germany"); std::locale::global(loc); po::parse_config_file(stream, opts, false); to parse the config file correctly. Best regards, Christoph [1] "http://www.boost.org/doc/libs/1_43_0/doc/html/program_options/howto.html#id…

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[chrono] v0.4.1 + thread_clock implementation on Windows
by vicente.botet 21 Jun '10

21 Jun '10

Hi all, As suggested by Roland Bock on the Boost Users ML, I have implemented the thread_clock on Windows using FILETIME creationTime, exitTime, kernelTime, userTime; GetThreadTimes(GetCurrentThread (), &creationTime, &exitTime, &kernelTime,&userTime); I don't know Windows well, it would be very kind if someone of you can inspect the implementation. The implementation of thread_clock for Mac is still missing. I don't know even if thread cloks are provided on this platform. In addition, I have added also the function prototypes to Boost.Thread using Boost.Chrono as well as updated the tests. This could be used as a base for a possible Boost.Thread update using chrono (standard C++0x proposal), if the library is accepted, of course. Note the modifications of Boost.Thread have been done on the base of 1.43. The library can be downloaded from http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… and the documentation is online on the sandbox http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht…. Anthony Williams has accepted to manage the review. We have not yet fixed a date, but I expect we could communicate one soon. I will be very thankful, if people using the library already or that could be interested in, can do a review even before the date. Thanks, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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[quickbook] All tests failing in Trunk?
by John Maddock 20 Jun '10

20 Jun '10

All the quickbook tests seem to currently be failing in Trunk, this appears to be related to some change in Boost.Build as the Jamfile logic used to work I believe? John.

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[iostreams] Thank you to Steven Watanabe
by eg 20 Jun '10

20 Jun '10

I just wanted to pass along a big thank you to Steven Watanabe for fixing a ton of bugs in the iostreams library this past week! According to Trac it appears there are only 13 Tickets left open (and this number was around 34 at the end of the recent bug sprint). From those of us who use the library, but haven't had the time or wherewithal to tackle these ourselves, this will be very helpful indeed. Thanks again! Regards, Ed

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Requests for comments on a (partly) hypothetical non-relational serialization library
by nathaniel＠photino.org 20 Jun '10

20 Jun '10

Hi all: I've been working for a while on a variety of tools to facilitate application development in normal (cross-platform) C++, and avoid the byzantine dependency chains (including needing multiple boost versions) which so often creep in because real applications always seem to piece together disparate parts with different build systems, requirements, even how to download the source code...pretty soon you're not programming C++ anymore, you're tinkering with Python make scripts, or Perl code generators, or learning Git or Subversion ... know what I'm saying? Anyhow, I'm a fan of the Mongo database, but it's notoriously hard to build even the drivers, and not really suited for simple SQLite-like object serialization for persistence between runs of an application (even though this is theoretically possible, it is poorly documented and still requires linking against the entire Mongo system). So I've decided to develop a serialization framework (not a database) with some "NoSQL" features based on Mongo, but alot easier to use. I believe this framework could provide a foundation upon which useful, moderately complex C++ applications could be designed, by providing extensions to the library which are optional to use but which incorporate my work (I hope that doesn't sound pedantic) on general application development, without extra external dependencies. Specifically, these extensions would include: 1) A tool for generating GUI code -- for wxWidgets, in particular -- from archives that could be edited with a simple textual front-end, vaguely like XAML; 2) A custom language based on Clojure -- a Lisp dialect originally implemented by Rich Hickey on the JVM -- for expressing queries and importing/exporting data from/to an archive; 3) Perl6-like regular expressions for matching against textual fields in an archive; 4) AI-inspired algorithms for sorting, filtering, and in other ways operating on archives. My academic background is in AI -- actually, to be precise, I wrote a doctoral dissertation in the philosophy of science, but I researched AI in this context -- but I'm especially interested in nonrelational database theory because it better captures the process of modeling complex systems, and, in general, nonrelational databases are more interesting from an AI perspective because the lack of a fixed schema means that operations like sorting and filtering can require some "reasoning". I'm particularly interested in application development because I think one concrete application of AI research is to make tools like IDEs smarter. A non-relational serialization library could potentially serve the application development process not only by providing an easy way to persist data, but through IDE extensions or project generators -- store lists of debug breakpoints in an archive, or parse source code for namespaces, types, etc., and store the results in an archive, or an archive to represent all the controls in a GUI... The library I have in mind would differ from boost.serialization by providing explicit support for non-relational functionality, and also by using a restricted type system along the lines of MongoDB and JSON: any persistable data field would have to be marshalled into one of a few predefined types, although users could explicitly extend the type system if desired. Aside from writing persistence code directly in the C++ source (along the lines of, e.g., instantiating a serialize() template in namespace boost::serialization), the test or demo applications I've been writing use external files, written in the (currently very minimal) Clojure-like language I mentioned above, and an interpreter does the actual serialization -- so the persistence strategy could be altered without recompiling the application, even while it is running. I think this offers new potential for using AI-style algorithms for things like tracking usage patterns, because all of that could be implemented fully orthogonal to the application itself. So, that's the project I've sort of assigned myself, and I would appreciate any comments and ideas and what I could do to make this the kind of library C++ programmers would consider trying out. Thanks in advance.

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