- Boost - lists.boost.org

Re: BOOST_LOG
by Reece Dunn 13 Nov '04

13 Nov '04

Eljay Love-Jensen wrote: > Hi Reece, > > You'd have to run the source code through the pre-processor twice to remove > the comments. > > Comments are stripped out first, then macro-expansion. (Not surprisingly, > Microsoft's compiler is non-compliant, and the trick works on their > platform.) How about: class null_log { public: template< typename T > null_log & operator<<( const T & ) { return *this; } }; null_log log; #define BOOST_LOG(id) log This should work and a good compiler should be able to optimize away the log output, leaving only the small footprint of the global variable. It also has the advantage of being multi-line compatible: BOOST_LOG(dbg) << "message: " << foobar; Regards, Reece

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[ANN] Format Lite
by Jonathan Turkanis 13 Nov '04

13 Nov '04

Dear All, I've just finished documenting a small library, available here: http://home.comcast.net/~jturkanis/format_lite/ It's a lightweight version of Reece Dunne's recently reviewed Output Formatters library. It was inspired by the discussion of Reece's library on this list and by the discussion of TR1 tuple i/o at the recent standards committee meeting in Redmond. ----- Format Lite is a lightweight, easy-to-learn framework for formatting data structures such as standard library containers and Boost tuples. It provides a reasonable degree of customizability with an emphasis on human-readable output formats useful for testing and debugging. A future version of Format Lite could be a candidate for incorporation into C++0x, to compensate for the lack of standard iostreams inserters and extractors for standard library containers, and to make existing inserters and extractors - such as those provided in <complex> - more flexible. Format lite provides three function templates: * boost::io::punctuate, used to specify punctuation sequences and options for line-breaks and indentation. * operator<<, used to insert ranges and tuple-like objects into standard output streams. * operator>>, used to extract ranges and tuple-like objects from standard input streams. ----- Best Regards, Jonathan

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Testing interest for a shared memory/STL library proposal
by Ion Gaztañaga 13 Nov '04

13 Nov '04

Hello to all, My name is Ion Gaztañaga, a telecommunication engineer working in railway industry R&D . I've been lately working on a CUJ article about placing STL containers (and any other object) in shared memory using smart pointers instead of raw pointers as allocator::pointer. The article has been accepted for a future issue and is currently in a editing/reviewing phase. Working in this article, I've created a library/framework, developing some classes that I think can be useful for a new boost library. I would like to know if there is any interested in boost for developing such classes, based or not in my article ideas or code. If there is any interest, I would be glad to present a boostified version of the library/framework for a review proccess. Currently, the framework uses these ideas: -> Relative pointers (smart pointers) for placing them in shared memory. -> OS basic mechanism abstractions: shared-memory creation, process-shared mutex, named semaphore -> Shared memory allocator for dynamic allocation/deallocation of parts of a shared memory segment. -> Named shared memory allocation manager, so that any process can look for an object in shared memory. -> Pooled shared memory allocator for node containers. -> Some STL-like container examples that can be placed in shared memory for systems with no smart-pointer allocator::pointer supporting STLs -> others... The framework works with Win32/Visual.NET 2003, QNX6.x/gcc-2.95.2,Mandrake Linux10.1/gcc-3.4.1 and partially (relative pointers and raw shmemory allocation) with Win32/VisualC++ 6.0. I've put a special full-length article in html and the source code in the file http://ice.prohosting.com/newfunk/boost_shmemSTL.zip, so that anyone can take a look. Please, you don't need to waste much time in the article, since I just want to know if contained ideas are interesting for boost. Please remember that some classes such as scoped-locks, etc... are in boost but I wanted the framework to be independent of any other library for this article. Of course, this would change in an hypotetic boostified version, since this is only to get an idea. Please, feel free to comment/critisize. Regards, Ion

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Boost Iterable Range Library update (v1.5)
by John Torjo 12 Nov '04

12 Nov '04

Dear boosters, I have updated the Iterable Range Library (formely known as Range Templates Library). It makes dealing with containers/STL algorithms simpler by using ranges (as opposed to iterators). Simply put, a range is a smarter std::pair<iterator,iterator>. Here's a taste: for ( crange<some_array_type> r(some_array); r; ++r) do_something( *r, some_data); Also, the library provides wrappers for all STL algorithms (for the purpose of STL algorithms, all containers are ranges as well): typedef std::vector<std::string> word_array; word_array v; // STL version std::copy( v.begin(), v.end(), print); // rng:: version rng::copy( v, print); Also, the counterparts for STL algorithms that return an iterator will return a range, allowing for: // fill a vector with all the indexes at which a certain string is found std::string str = "I'm a cool programmer, really cool that is", find = "cool"; std::vector<int> result; crange<std::string> r(str); while ( r = rng::search(r, find)) result.push_back ( r.begin() - str.begin() ); And it provides for range adaptors, allowing for composition. bool from_ro(const employee & e) { return e.country == "Romania"; } std::string get_empl_name(const employee &e) { return e.name; } typedef std::vector<employee> array; array empls; // take all employees from Romania, and print their names rng::copy( transformed( filtered(empls,from_ro), get_empl_name), std::ostream_iterator<std::string>(std::cout," ")); Changes in this version: - improved algorithms.hpp (no more use of macros) - solved small bugs - added documentation Download it from here: http://www.torjo.com/rangelib/ Feedback is welcome. Best, John -- John Torjo, Contributing editor, C/C++ Users Journal -- "Win32 GUI Generics" -- generics & GUI do mix, after all -- http://www.torjo.com/win32gui/ -- v1.5 - tooltips at your fingertips (work for menus too!) + bitmap buttons (work for MessageBox too!) + tab dialogs, hyper links, lite html

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Re: Generalised reflection
by George van den Driessche 12 Nov '04

12 Nov '04

> Message: 4 > Date: Fri, 12 Nov 2004 07:34:27 -0500 > From: "Neal D. Becker" <ndbecker2(a)verizon.net> > Subject: [boost] Re: Generalised reflection > To: boost(a)lists.boost.org > Message-ID: <cn2akj$qij$1(a)sea.gmane.org> > Content-Type: text/plain; charset=us-ascii > > George van den Driessche wrote: > > [...] > > Yes. Now imagine that I've got some helper functions for use with > > Boost.Python's pickling suite. But I want to use them with a C++ > > serialisation library. I'm going to have to factor a bunch of code out of > > those helper functions so that I can invoke them without using > > boost::python::tuple, and then write wrappers to use the factored-out code > > with the Boost.Python pickling suite. Instead, I want to write just the > > C++ serialisation code, and have that automatically wrapped up for use > > with Boost.Python pickling. It's a similar separation of layers. > > > > Incidentally, I wrote about sharing boost c++ serialization with > boost.python pickling, and posted code demonstrating this. Nobody seemed > very interested. I think it's this post: http://tinyurl.com/6dbhb that you're referring to. In which case, I missed it, but yes, you're on the same topic. One of the things that I noticed about serialisation code is that there's generally a symmetry between the reading and writing routines. So rather than write "this is how I load an X, and this is how I save one" I'd want to write "these are the things in X that need to be saved" and let some templates figure out what the corresponding routines are. And then it was this desire to serialise things automatically by specifying properties that led me on to think about a common architecture for language binding and serialisation. Maybe in the end you'd get declarations like: /// Properties for serialisation boost::properties< my_t, "my_t", boost::serialisation > .def( "my_int", &my_t::my_int, &my_t::set_my_int ) // After serialisation format version 4, // my_float no longer needed to be serialised .def( "my_float", &my_t::my_float, &my_t::set_my_float, boost::serialisation::in_format_version_range<>( 0, 4 ) ) ; /// Properties for scripting boost::properties< my_t, "my_t", boost::langbinding > // Use serialisation properties to implement pickling. .def_pickle( default_pickle_suite< my_t >() ) .def( "my_int", &my_t::my_int, &my_t::set_my_int, boost::langbinding::return_internal_reference<>() ) // We don't want to bind my_float, for whatever reason. ;

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RE: [boost] [Review] Named parameters library
by Aleksey Chernoraenko 12 Nov '04

12 Nov '04

Hello, >[...] > http://groups.yahoo.com/group/boost/files/named_params.zip Is it possible to make a copy to somewhere else, more accessible place (http://sourceforge.net/projects/boost/) ? ---- Thank you, Aleksey Chernoraenko

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[library process] should we more actively pursue university thesis projects?
by Thorsten Ottosen 12 Nov '04

12 Nov '04

Dear all, Following our discussion of the unicode library, would it not be a good idea to persue such efforts more aggresively? I could imagine it would help bring forward libraries much faster. I think it would be reasonable that the boost comunity provided 1. project descriptions 2. help and guidelines throughout the 6-12 months of the project If we had small papers explaining potential projects, these can be sent to universities which can the in turn suggest them to their students. Off the top of my head, I can think of these projects 1. C++ database library 2. C++ statistics library 3. exact reals class 4. An XML parser and generator library I could probably be a co-author and contact person of (2). Any thoughts? -Thorsten

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logging lib, v1.3
by John Torjo 12 Nov '04

12 Nov '04

Dear boosters, Finally, have had some time to update the logging lib. Get it from: http://www.torjo.com/ (of course, it comes packed with docs) First of all, many thanks to Darryl Green and Caleb Epstein! Summary - solved a few bugs - redesigned so that I allow for scoped logs (no more log IDs, now logs are identified by a 'string name') - ported the code from Caleb - allow for a "log manager" (many thanks to Darryl Green!) (it is not documented yet, but will do so as soon as I have some time) - updated docs - (renaming) add_modifier_func -> add_modifier (renaming) add_logger_func -> add_appender - thread-safety update (again, many thanks to Darryl Green!) - you can log messages even *before* logs are initialized after logs are initialized, just call flush_log_cache(); As for scoped logs, to make a long story short, you'll be able to do: logger gui("app.gui") if (gui) gui.stream() << "something GUIsh"; // or (equivalent) BOOOST_SCOPEDLOG(gui) << "something GUIsh"; Still to do: - docs: write about log managers - cyclic logs Looking forward to your feedback! Best, John -- John Torjo, Contributing editor, C/C++ Users Journal -- "Win32 GUI Generics" -- generics & GUI do mix, after all -- http://www.torjo.com/win32gui/ -- v1.5 - tooltips at your fingertips (work for menus too!) + bitmap buttons (work for MessageBox too!) + tab dialogs, hyper links, lite html

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boost::weak_ptr
by Dirk Gregorius 12 Nov '04

12 Nov '04

Is it possible to reset a boost::shared_ptr without all associated boost::weak_ptr become invalid? -Dirk

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boost::function feature request?
by Peter Dimov 12 Nov '04

12 Nov '04

When using boost::function<bool()> to implement event callbacks such as is_visible or is_enabled, it's very convenient to pass 'true' or 'false' directly, instead of going through bind( identity<bool>(), true ). An UI button I recently did even had separate bool properties in addition to the callback events for these reasons. I wonder whether it's reasonable to add this_type& operator=( T const & t ); to function<T()> that does the obvious thing. Of course f = t; is merely a shorthand way of spelling f = boost::lambda::constant(t), but a dependency on lambda isn't always desirable. Thoughts? -- Peter Dimov http://www.pdimov.com

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