October 2007 - Boost - lists.preview.boost.org

boost::optional<T &>::get_ptr()
by Preston A. Elder 23 Oct '07

23 Oct '07

When was this made to NOT work? I am compiling an app against the CVS head of boost, because I want to use things like property_tree, and I don't plan on releasing my app before boost 1.35 is released anyway. But apparently, boost::optional<T&>::get_ptr() no longer works. Now instead I have to use if (myopt && &myopt.get() == &obj) instead of the terser: if (myopt.get_ptr() == &obj) I can't see anything about this in the dev list, and the docs on boost.org (which granted are for 1.34.1) still list get_ptr() as working for both optional<T> and optional<T&>. Preston

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[review] Exception - review period extended
by Tobias Schwinger 23 Oct '07

23 Oct '07

The review period of the proposed Exception library has been extended until October 20th. Although several people seemed interested in the submission, we only have two votes, so far. So we really need more votes. Further, I'm concerned about some potential issues, which I wouldn't want to bless into Boost without being sure there has been a thorough investigation (see below). So, I want to encourage you to evaluate the submission, in particular regarding the following questions: 1. Should the library be accepted as a Boost library? For a guideline on what to include in your evaluation see http://www.boost.org/more/formal_review_process.htm 2. Is the design of the 'enable_error_info' function (see http://www.revergestudios.com/boost-exception/boost-exception.htm#existing_… and http://www.revergestudios.com/boost-exception/boost-exception.htm#enable_er… ), using multiple inheritance, really sound? 3. Does the current implementation use appropriate data structures? We are looking forward to your reviews! Regards, Tobias Schwinger - Review Manager -

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Exception late review
by Alexander Nasonov 23 Oct '07

23 Oct '07

I don't know if review manager still accepts reviews as review period is over but I'd like to share my ideas with others. I'm very interested in this library but I don't think that this version is good enough for inclusion into boost. As already pointed out by many people, library name is misleading. I'd expect from a library named Boost.exception that: - it provides functionality missing in std::exception (clone is one example), - it recommends deriving all boost exception classes from boost::exception and - wrapping standard exceptions with correspondent boost exceptions in boost::throw_exception. The library doesn't have enough features to cover problem domain or they are not well documented. Example shows how to attach additionaly information to FILE but it would be much better to demonstrate how information is added at each layer and then presented to end user. One example is RDBMS where some exception is raised at OS layer (e.g. file system full), then caught at db storage layer, rethown, then caught at higher layere up to SQL layer where it's nicely presented and send to a user. This case should cover tags associated with layers. Other important case is stacking up information as an exception is being processed. Stack trace is a good example. Also, it should be clear how library handle bad_alloc. In some situations, it's fine to rethrown bad_alloc instead of original exception but more fine tuned behavior is require in other situations. One example is stop adding info to a stack and just count all not added stack entries. Sorry for not very well detailed review and for being too late. I was hoping to find time and think thoroughly about interface but I couldn't find enough time. -- Alexander

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[xpressive] Failures on the release branch
by Darren Garvey 23 Oct '07

23 Oct '07

It looks like a lot of the xpressive test fails come from missing files. See: *http://tinyurl.com/276jfw* eg. ../boost/xpressive/detail/static/compile.hpp:26:65: error: boost/xpressive/detail/static/productions/visitor.hpp: No such file or directory ../boost/xpressive/detail/static/compile.hpp:27:69: error: boost/xpressive/detail/static/productions/domain_tags.hpp: No such file or directory In file included from ../boost/xpressive/xpressive_static.hpp:24, from ../boost/xpressive/xpressive.hpp:18, from ../libs/xpressive/test/misc1.cpp:9: ../boost/xpressive/regex_primitives.hpp:24:69: error: boost/xpressive/detail/static/productions/productions.hpp: No such file or directory These three particular files are in svn release branch (and always seem to have been), but they're not all in the trunk. The fails are for the release branch apparently, so I'm not sure why they break. visitor.hpp is in the trunk, but is 'one directory up' (ie. cp visitor.hpp..), while the 'productions' dir isn't in the trunk at all. Regards, Darren

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build boost 1.34.1 with stlport ?
by Bernd Martin Wollny 23 Oct '07

23 Oct '07

Hello, I just tried to upgrade from boost 1.33 to 1.34.1 In the old boost version you can use -sTOOLS=msvc_71-stlport -sSTLPORT_VERSION=51.4 .,...... It's seemd that the syntac has changed but .. you can not find this changes in the documentation. Can some one help me how i can compile boost 3.1.4 with MS VC7.1 and stlport ??? bye bernd -- Bernd Martin Wollny TRIOPTICS GmbH - www.trioptics.com b.wollny(a)trioptics.com Hafenstrasse 39, 22880 Wedel/GERMANY Software Designer Geschäftsführer: Dipl.-Ing. Eugen Dumitrescu phone / fax: +49 (0)4103 18006-26 /-20 Amtsgericht Pinneberg HRB 3215 All E-Mails from bm.wollny(a)trioptics.com are digital signed. If you get a unsigned E-Mail, this E-Mail are a fake. Look at http://www.gnupg.org .

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[interprocess] managed_memory_impl.hpp
by Markus Schöpflin 23 Oct '07

23 Oct '07

This file contains at line 246: return instream.read(detail::char_ptr_cast(this->get_address()), (std::streamsize)this->get_size).good(); This most probably should read this->get_size(), but as no compiler besides cxx caught this error, I'm wondering if this code is ever used at all? Regards, Markus

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For inclusion to boost::function
by Preston A. Elder 23 Oct '07

23 Oct '07

(repost, I accidentally posted this to boost::build list ... ugh). I have written code to solve this problem: I have class foo, like so: class foo { boost::function<void (foo *)> func_ptr; void call() { func_ptr(this); } }; I want func_ptr to be either a free-standing function (or class static), OR a class member function of a derived class, so: void bar(foo *f) { ... } OR: class baz : public foo { public: baz() { func_ptr = &baz::doit; } void doit() { } }; The obvious problem with the latter is that it needs to be downcast implicitly, and some kind of exception thrown if the wrong type is passed. I have created a boost::function proxy class to handle exactly this problem. It uses a lot of boost::function's own tricks with the pre-processor and such. I also had to use another suggestion I saw on this list to work around the fact boost::function does not accept member function pointer syntax (argh! That took a lot to figure out). My solution is this: http://www.neuromancy.net/fisheye/browse/mantra/trunk/Mantra-I/mantra/utils… Which is included by a boost preprocessor iteration here: http://www.neuromancy.net/fisheye/browse/mantra/trunk/Mantra-I/mantra/utils… As I mention, I use a lot of boost::function's own tricks. I think this would be a lot cleaner if done as part of boost::function, rather than me re-implementing the same macros and such. I have made sure my implementation works, and more importantly, has all the tests you would expect (ie. that the return value arguments except the class are the same, that the class is derived from the original function typedef's first argument, and so on). Here is my test case: http://www.neuromancy.net/fisheye/browse/mantra/trunk/Mantra-I/test/schedul… Any way, feedback is as always appreciated, but if someone could look at this for an addition to boost::function it would really be great PreZ

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[system] Possible breakage: naming changes to conform to C++ std
by Beman Dawes 23 Oct '07

23 Oct '07

At the Kona meeting two weeks ago, the C++ committee accepted most of the Diagnostics changes proposed in N2415. See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2415.html Most of Boost.System doesn't change since it already reflects N2415. The committee did, however, change the name of the nested "posix" namespace to "posix_error". For consistency, that means the "Linux" namespace changes to "linux_error" and the "windows" namespace changes to "window_error". As a consequence, the "linux_error" enum changes to "linux_errno". To minimize code breakage, I've added namespace aliases to error_code.hpp: # ifndef BOOST_SYSTEM_NO_DEPRECATED namespace posix = posix_error; # endif # ifndef BOOST_SYSTEM_NO_DEPRECATED namespace Linux = linux_error; # endif # ifndef BOOST_SYSTEM_NO_DEPRECATED namespace windows = windows_error; # endif That was sufficient to prevent any code breakage in the Boost.System and Boost.Filesystem test code, but any user code that actually mentions the linux_errno enum (rather than its constants) will have to be changed. --Beman

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License in boostbook generated HTML pages
by John Maddock 23 Oct '07

23 Oct '07

I note we have a requirement - enforced by the inspect tool - for all HTML doc pages to display the boost license somewhere. However, quickbook/boostbook generated docs only place the license info on the first page. Is this something that needs fixing, or are our requirements too strict? While we're at it, it would be nice if the revision information was in the footer of each page as well :-) John.

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[math] typo in special_functions/fpclassify.hpp rev. 40321
by Boris Gubenko 23 Oct '07

23 Oct '07

math library tests failed on HP-UX because of typo in math/special_functions/fpclassify.hpp rev. 40321. I've fixed it in rev. 40323. Thanks, Boris

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