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return type of arithmetic operators
by beckmann.bremen＠t-online.de 08 Aug '04

08 Aug '04

Hi, I want to use the arithmetic operators from boost/operators.hpp but found something strange. If one takes for example boost::rational which uses boost::addable (and others), it is possible to write the following: boost::rational<int> x, y, z; x + y = z; This is not possible for integral types. Is this intended, considered minor or just overseen? Wouldn't it be better for the arithmetic operators to return const T instead of T? Thank you in advance, Thomas

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[1.32 Plan] release status?
by JOAQUIN LOPEZ MU?Z 08 Aug '04

08 Aug '04

Hi all, I have only limited access to the list these days, so my apologies if there's been some progress in this area that I missed to read about. Are we ready to schedule a final deadline for branching? >From what Alexsey stated last week, I understand we are now in a position to inspect results for all the relevant platforms, and the turnaround cycle is kept under a healthy 24 hours. The issues reports show regressions (red cells) for only five libraries, and the number of yellow cells is, IMHO, resonable, given the many exotic compilers that have been recently introduced in the regression tests. OTOH, the release date has slipped over three weeks now, and I guess we cannot just go on forever fixing things, as it is not realistic to expect that every issue be resolved in a reasonable amount of time. Maybe having some fixed schedule for branching will help concentrate on those problems that are really important. Just my 2 cents. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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concept_check: abnormal termination on CW 8.3?
by Stefan Slapeta 07 Aug '04

07 Aug '04

This concept_check test case http://tinyurl.com/5q3zk on CW 8.3 looks like an abnormal termination. Please could somebody with access to this compiler verify that? Stefan

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[serialization] CW8 and the recent changes...
by Rene Rivera 07 Aug '04

07 Aug '04

The most recent changes cause a large number of new warnings to show up. The are all of the form: ### mwcc Compiler: # In: ..\boost\serialization\void_cast.hpp # From: ..\libs\serialization\test\test_array.cpp # -------------------------------------------------- # 188: __declspec(noinline) __declspec(dllexport) # Warning: ^^^^^^^^ # illegal type qualifier(s) # (included from: # base_object.hpp:30 # nvp.hpp:26 # interface_oarchive.hpp:26 # common_oarchive.hpp:20 # basic_xml_oarchive.hpp:28 # xml_oarchive.hpp:30 # xml_archive.hpp:8 # test_tools.hpp:108 # test_array.cpp:20) -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org - grafik/redshift-software.com - 102708583/icq

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[boost.thread] regression on vc7.1
by Bronek Kozicki 07 Aug '04

07 Aug '04

Apparently there's some problem with tss on vc7.1, see http://tinyurl.com/5zqrs . I will look into it later today. I hope that we still have time to fix it, no need to pull static library support out of release 1.32. B.

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bgl connected_components ComponentMap
by Andreas Fabri 07 Aug '04

07 Aug '04

Hi, I wrote my own property map class, and wanted to use it in the connected_component function, in order to retrieve the components. When it didn't work, I realised that the component map is copied internally, that is the result was written in the copy. I have an obvious solution for this, but I am nevertheless wondering if I missed something in the definition of the property map concept, or the connected_component class. thank you in advance, andreas

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JavaScript Menu for BoostBook
by Reece Dunn 07 Aug '04

07 Aug '04

Hi all, I have attached a patch that will add support for the JavaScript Menu by Jonathan Turkanis to BoostBook. It generates frame.html and menu.html, leaving index.html unchanged. The tree control files are set as tree.js and tree.css. These are searched for in the directory provided by the toc.treecontrol xsl:param (set to ./tree as default). Regards, Reece _________________________________________________________________ Express yourself with cool new emoticons http://www.msn.co.uk/specials/myemo

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[dynamic_bitset] CW8 regression, a plea for help!
by Rene Rivera 06 Aug '04

06 Aug '04

In running my set of _release_ mode tests I ran into a regression for dynamic_bitset, you can see it here (the RSI results): http://www.meta-comm.com/engineering/boost-regression/developer/dynamic_bit… Boost regression: dynamic_bitset/CVS-HEAD This is a new regression... I just also ran the tests for the dynamic_bitset in 1.31.0, and 1.30.2 (this is the version I currently use in my production code) -- And both of those pass. I'm asking for help in tracking this down. I'm not familiar at all with the dynamic_bitset code so some direction as to likely causes of the problems, or where to start looking are much appreciated. For now I'll just be single stepping through the code, oh fun :-( -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org - grafik/redshift-software.com - 102708583/icq

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[boost.thread] at_thread_exit must be serialized?
by Roland 06 Aug '04

06 Aug '04

Dear Mike, could you please give me the reasoning why the cleanup handlers that are specified in at_thread_exit must be serialized? It turns out that this is caused by a mutex located in on_thread_exit. Essentially this prohibits more than an exit handler chain to run at the same time. While there might be sound reasons for this I'd like to know please. How did I run into this: I wanted to bind the lifetime of a second thread to the one who started it. So I did soemthing like: void start(void) { if (!at_thread_exit(stop)) syslog_thrd = new cthread::cancelable_thread(&syslog_run); } The stop function beeing declared as: void stop(void) { if (syslog_thrd) { syslog_thrd->cancel(); syslog_thrd->join(); delete syslog_thrd; syslog_thrd = 0; } } When my first thread is exiting now, the stop is getting called properly. However my cancel causes the thread to exit (calling into its exit handler chain in turn). This will of course cause deadlock (altough in an non obvious way) since stop also has been called from the exit handler chain. The thread cannot be joined because it does not really end. You see? Perhaps you even can suggest another solution to my problem? Regards, Roland

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Proposal for New Iterator Adaptor
by Alex Chovanec 06 Aug '04

06 Aug '04

I realize that this isn't the best time for proposals, what with everyone trying to get the next release of boost out, but I have an idea for a new iterator adaptor which I'd like to propose. Consider an adapted iterator type Iter with base iterator type Base that has the following traits: typedef Base value_type; typedef const Base & reference; When you dereference an instance of the adapted iterator type Iter, you get a const reference to its base iterator of type Base. So instead of delegating the dereference operation to its base and returning the result, the iterator adaptor simply returns its base. Since it doesn't dereference its base, I would probably name it "lazy_iterator", or something like that. There are some interesting things that you can do with this. For example: typedef std::vector< CString > vector; typedef std::vector< vector::iterator > iter_vector; typedef lazy_iterator< vector::iterator > lazy_iter; vector my_vector; iter_vector my_iter_vector; ... std::unique_copy( lazy_iter( my_vector.begin() ), lazy_iter( my_vector.end() ), std::back_inserter( my_iter_vector ), indirect_equal_to()); where indirect_equal_to is a special binary predicate which is defined like this: struct indirect_equal_to { template <typename Iter> bool operator==(Iter a, Iter b) { return *a == *b; } }; After this call to std::unique_copy(), my_iter_vector is a sequence of iterators that point to the unique elements in my_vector. Typically, you would just copy the unique elements into another vector of strings, but the approach described here is advantageous if you need to access the original unique elements in my_vector (for instance, if you need to change them), or if you want to avoid the overhead of copying strings. You could also have an iterator adaptor type Iter whose dereferencing operator returns &(*b), where b is its base iterator of type Base. This could be useful for generating ranges of pointers from ranges of objects. I think that this would be a useful iterator adaptor that would complement indirect_iterator very nicely. Whereas indirect iterator is useful for performing operations on ranges of iterators, this adaptor is ideal for generating ranges of iterators. Is anyone else interested in this? Thanks, Alex Chovanec

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