- Boost - lists.boost.org

[multi_index] intrusive multi_index poll for interest
by Maxim Yegorushkin 20 Jan '06

20 Jan '06

Motivation Existing practice have shown the need for intrusive containers. Widely used C++ libraries, such as C++ Standard Library and Boost have long missed such facilities so that users had to refrain from using those due to mandatory element copying or fall back to techniques like two phase construction to insert logically non-copyable elements in containers and initialize them after that or insert pointers to dynamically allocated objects which is rather inelegant and inefficient since containers also dynamically allocate nodes. The most common use cases for intrusive containers are: * when one would like to store non-copyable elements in a container * when it's beneficial to avoid needless data copy in performance critical applications The most prominent example of both the use cases, although written for the most part in C rather than C++, is Linux kernel built solely upon intrusive lists, hash tables and trees. Basic usage An intrusive container is not a container in a stl sense, since it does not own its elements. The sole purpose of an intrusive container is to establish ordering between elements. It's a user responsibility to keep an intrusive container up-to-date by calling replace() to alter fields upon which an order is established as well as erase the nodes from the container prior to node's destruction. Aside from that the look and feel are similar to those of an non-intrusive container. Here is how one would declare an intrusive container, an intrusive node and insert removes nodes: struct record; typedef multi_index_container<intrusive<record> > container; struct record : container::node_type {}; bool operator<(record const& a, record const& b); void insert_sample(container* c) { std::auto_ptr<record> p(new record); if(c->insert(*p).second) p.release(); } void erase_sample(container* c, container::iterator pos) { std::auto_ptr<record const> p(&*pos); c->erase(pos); } Here is how one would make a multi-node, i.e. a node that can be enlisted into several containers simultaneously: struct record; struct tag1; struct tag2; typedef multi_index_container<intrusive<record, tag1> > container1; typedef multi_index_container<intrusive<record, tag2> > container2; struct record : container1::node_type, container2::node_type {}; inline bool operator<(record const& a, record const& b); void insert_sample(container1* c1, container2* c2) { struct guard { container1* c1; container2* c2; std::pair<container1::iterator, bool> i1; std::pair<container2::iterator, bool> i2; std::auto_ptr<record> p; ~guard() { if(i1.second && i2.second) { p.release(); } else { c1->erase(i1.first); c2->erase(i2.first); } } guard(container1* c1, container2* c2, std::auto_ptr<record> p) : c1(c1), c2(c2), i1(c1->end(), 0), i2(c2->end(), 0), p(p) {} } guard(c1, c2, std::auto_ptr<record>(new record)); guard.i1 = c1->insert(*guard.p); guard.i2 = c2->insert(*guard.p); } void erase_sample(container1* c1, container2* c2, record* r) { c1->erase(c1->make_iterator(r)); c2->erase(c2->make_iterator(r)); delete r; } The examples are included in test_intrusive.cpp. Current implementation Current implementation although efficient and mostly functional is a proof of concept only. Further design work is required which we rather unclear about and therefore would like to poll for interest and suggestions. Known limitations: * partial template specialization support is required * dereferencing an intrusive container iterator yields a constant, should probably return non-constant * safe mode is not implemented for make_iterator() exposed api http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam…

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[Review] Formal review of Fixed Strings library starts today
by Hartmut Kaiser 20 Jan '06

20 Jan '06

Hi all, The review of the proposed Boost Fixed Strings library written by Reece Dunn starts today (January 19th, 2006) and ends January 28th, 2006. You can download the library here: http://tinyurl.com/czrh9 --------------------------------------------------- About the library: The fixed_strings library is a buffer-overrun safe version of using fixed-size character array data buffers. It provides integration with the C API allowing strcpy, et. al. to be used safely for a fixed string and provides a basic_string interface allowing easy migration to C++ strings. There is also a formatter function object allowing (w)sprintf to be used in a single line! Example: boost::fixed_string< 5 > hi; strcpy( hi, "Hello World" ); hi.push_back( '!' ); std::cout << hi << std::endl; std::cout << boost::formatter( "Meine %s Welt!", "kleine" ) << std::endl; output: Hello Meine kleine Welt! --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards Hartmut Review Manager

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[python] type attributes in forward declarations
by Jody Hagins 20 Jan '06

20 Jan '06

Class declarations like this... class BOOST_PYTHON_DECL wrapper_base; are causing compiler warnings on gcc 4.0.2 with a warning like: type attributes are honored only at type definition However, I see this is also used to handle the insane import/export windows DLL stuff. Since I do not do much compilation on the windows platforms anymore, is the BOOST_PYTHON_DECL really necessary in the forward declaration, or is it just a convention? Thanks!

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pointer container library: extra semicolon
by Oliver Kullmann 20 Jan '06

20 Jan '06

Hi, I get a compiler error because of an illegal semicolon: boost-1_33_1/boost/ptr_container/ptr_map_adapter.hpp:180: error: extra ‘;’ Command exited with non-zero status 1 Removing that semicolon solves the problem. (There was a discussion some time ago about these semicolons at namespace scope, which many compilers ignore; I think it was commonly accepted finally to get rid off those.) Oliver

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[pimpl] : Problem in compiling using gcc 3.4.4.
by nitin motgi 20 Jan '06

20 Jan '06

Hi Asgar, I was compiling pimpl test on Cygwin with g++ 3.4.4 and was failing due to some compiler errors. I fixed and thought you should also know it before getting into review. Please let me know if you need any help. Attached is the diff file. $ g++ -v Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs Configured with: /gcc/gcc-3.4.4/gcc-3.4.4-1/configure --verbose --prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --enable-languages=c,ada,c++,d,f77,java,objc --enable-nls --without-included-gettext --enable-version-specific-runtime-libs --without-x --enable-libgcj --disable-java-awt --with-system-zlib --enable-interpreter --disable-libgcj-debug --enable-threads=posix --enable-java-gc=boehm --disable-win32-registry --enable-sjlj-exceptions --enable-hash-synchronization --enable-libstdcxx-debug : (reconfigured) Thread model: posix gcc version 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125) 1. First of all the pimpl_ptr.hpp is in the wrong directory. Possible location I think would be best is BOOST_ROOT/boost/pimpl_ptr.hpp 2. Some character at 27:7 in test/pimpl_ptr_test.h causes a compiler problem. 3. With 3.4.4 GCC dependent name lookup cause the problem because of which the base class variable you have defined m_pImpl is not reachable from derived class for policies. I modified it to this->m_pImpl everywhere in the derived classes and was able to compile. You can also qualify it completely. 4. And in the pimpl_ptr the same problem exists with get() function which should be calling the policy function. They are also subjected to two stage lookup causing compiler error. I has had to fix it by adding this-> in the beginning. 5. For the above points you need to possibly make necessary changes to accomodate compilers that do not have / or implement two-stage name lookup correctly. Thank you, -- Nitin Motgi NITIN . DOT. MOTGI .AT. GMAIL .DOT. COM

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Re: [boost] Interest for policy based smart pointer (smart_ptr)
by boost 20 Jan '06

20 Jan '06

"Larry Evans" <cppljevans(a)cox-internet.com> wrote in message news:<dqpagd$mov$1(a)sea.gmane.org>... > On 01/19/2006 05:13 PM, David Maisonave wrote: > [snip] > > I read in a previous thread that a policy base smart pointer was > > being considered for boost, but I could not find it in the sandbox. > http://cvs.sourceforge.net/viewcvs.py/boost-sandbox/boost-sandbox/boost/poli cy_ptr/ 1. Is there any usage documentation? 2. Has any performance test comparison been done? 3. Can it compile to VC++ 6.0? It looks like work started on this in 2004, but I don't see any logging pass 26 Jun 2005. 4. Is the work for this class at a stand-still?

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Interest for policy based smart pointer (smart_ptr)
by David Maisonave 20 Jan '06

20 Jan '06

I'm looking for what type of interest is there for a policy base smart pointer like that in the following link: http://code.axter.com/smart_ptr.h I read in a previous thread that a policy base smart pointer was being considered for boost, but I could not find it in the sandbox. The above policy base smart pointer is different from other similar smart pointer in that it does not inherit any of the policies. Only one of the policies (OWNERSHIP_POLICY) is used as a data member. The remaining policies use a static member function interface. This allows for the following type of declaration: smart_ptr<Shape, deep_copy_policy, clone_function_allocator_policy> pShape; Instead of this: smart_ptr<Shape, deep_copy_policy<Shape> , clone_function_allocator_policy<Shape> > pShape; or worse: smart_ptr<Shape, deep_copy_policy<Shape, clone_function_allocator_policy<Shape> > > pShape; The above smart pointer currently has copy_on_write_policy, shared_ptr_policy, deep_copy_policy. Moreover, these three types are interchangeable with each other. Smart_ptr currently uses reference-link logic, and on my performance test I found them to be able to out perform boost::shared_ptr on initialization and on copying. It would not be that hard to add reference-count ownership policy class, but I haven't found any real benefit to using reference-count other then size. The ALLOCATOR_POLICY can be used for both special allocators, and for using different cloning methods. Most clone function methods can only catch slicing at runtime. But the clone_static_function_allocator_policy can be used to help stop slicing at compile time. It's still not fail proof, but it's close. I'm still working on the cow_ptr, shared_ptr, and ptr_vector comparison article, but I'm looking to throw this smart_ptr into the mix, and wanted some feedback on it. Thanks

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Boost Review Wizard's Report: January 2006
by Ronald Garcia 19 Jan '06

19 Jan '06

Review Wizard Status Report for January 2006 Tom Brinkman Ronald Garcia 1) News 2) Review Managers Needed 3) Review Queue 4) Libraries Under Development //////////////////////////////////////////////////////////////////// 1) News //////////////////////////////////////////////////////////////////// Happy New Year! Here are some statistics regarding Boost Library reviews in 2005: - 12 Libraries were reviewed - 8 Libraries were accepted - 1 Library (Function Types) was accepted pending a mini-review - 2 Libraries were rejected - 1 Library has yet to receive a final verdict (ASIO) Policy Pointer has been removed from the review queue because the author has stated that it is not quite ready. We need review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. If you can serve as review manager for any of them, send one of us an email. Note: If you have any suggestions about how we could improve the Review Wizard's status report, please email "reportbase at gmail dot com" and "garcia at cs dot indiana dot edu". //////////////////////////////////////////////////////////////////// 2) Review Managers Needed //////////////////////////////////////////////////////////////////// There are a few libraries in the review queue in need of review managers. If you would like to volunteer to be a review manager, please contact Ron or Tom. The following libraries still require review managers: Fusion Shmem Pimpl Pointer Type Traits (modification) Function Types //////////////////////////////////////////////////////////////////// 3) Review Queue //////////////////////////////////////////////////////////////////// Fixed Strings - January 19 2006 - January 28 2006 Intrusive Containers Function Types (mini-re-review) Shmem Fusion Pimpl Pointer Type Traits (modification) Fixed Strings Author - Reece Dunn Review Manager - Harmut Kaiser Download: Boost Sandbox (http://boost-sandbox.sourceforge.net/) under fixed_string Description: The fixed string library provides buffer overrun protection for static sized strings (char s[ n ]). It provides a C-style string interface for compatibility with C code (for example, porting a C program to C++). There is also a std::string-style interface using a class based on flex_string by Andre Alexandrescu with a few limitations due to the non-resizable nature of the class. Intrusive Containers Author - Olaf Krzikalla Review Manager - to be determined Download: http://people.freenet.de/turtle++/intrusive.zip Description: While intrusive containers were and are widely used in C, they became more and more forgotten in the C++-world due to the presence of the standard containers, which don't support intrusive techniques. Boost.Intrusive not only reintroduces this technique to C++, but also encapsulates the implementation in STL-like interfaces. Hence anyone familiar with standard containers can use intrusive containers with ease. Function Types (mini-re-review) Author - Tobias Schwinger Review Manager - to be determined Download: http://boost-sandbox.sourceforge.net/vault/ Description: This library provides a metaprogramming facility to classify, decompose and synthesize function-, function pointer-, function reference- and member function pointer types. For the purpose of this documentation, these types are collectively referred to as function types (this differs from the standard definition and redefines the term from a programmer's perspective to refer to the most common types that involve functions). The classes introduced by this library shall conform to the concepts of the Boost Metaprogramming library (MPL). The Function Types library enables the user to: * test an arbitrary type for being a function type of specified kind, * inspect properties of function types, * view and modify sub types of an encapsulated function type with MPL Sequence operations, and * synthesize function types. This library supports variadic functions and can be configured to support non-default calling conventions. Shmem Author - Ion Gaztanaga Review Manager - to be determined Download: Boost Sandbox Vault -> Memory (http://boost-sandbox.sourceforge.net/vault/index.php? direction=0&order=&directory=Memory) http://ice.prohosting.com/newfunk/boost/libs/shmem/doc/html/index.html Description: Shmem offers tools to simplify shared memory usage in applications. These include shared memory creation/destruction and synchronization objects. It also implements dynamic allocation of portions of a shared memory segment and an easy way to construct C++ objects in shared memory. Apart from this, Shmem implements a wide range of STL-like containers and allocators that can be safely placed in shared memory, helpful to implement complex shared memory data-bases and other efficient inter-process communications. Fusion Author - Joel de Guzman Review Manager - to be determined Download: http://spirit.sourceforge.net/dl_more/fusion_v2/ Description: Fusion is a library of heterogenous containers and views and algorithms. A set of heterogenous containers (vector, list, set and map) is provided out of the box along with view classes that present various composable views over the data. The containers and views follow a common sequence concept with an underlying iterator concept that binds it all together, suitably making the algorithms fully generic over all sequence types. The architecture is somewhat modeled after MPL which in turn is modeled after STL. It is code-named "fusion" because the library is the "fusion" of compile time metaprogramming with runtime programming. Pimpl Pointer Author - Asger Mangaard Review Manager - to be determined Download: Boost Sandbox (http://boost-consulting.com/vault/) under pimpl_ptr. Description: The pimpl idiom is widely used to reduce compile times and disable code coupling. It does so by moving private parts of a class from the .hpp file to the .cpp file. However, it's implementation can be tricky, and with many pitfalls (especially regarding memory management). The pimpl_ptr library is a single header file, implementing a special policy based smart pointer to greately ease the implementation of the pimpl idiom. Type_Traits (modification) Author - Alexander Nasonov Review Manager - To be determined Download : You can download it from http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz or browse it online http://cpp-experiment.sourceforge.net/promote-20050917/ Description: Proposal to add promote, integral_promotion and floating_point_promotion class templates to type_traits library. Alexander tried it on different compilers with various success: GNU/Linux (gentoo-hardened): gcc 3.3 and 3.4, Intel 7, 8 and 9 Windows: VC7 free compiler Sparc Solaris: Sun C++ 5.3 and 5.7 See comments at the beginning of promote_enum_test.cpp for what is broken. http://cpp-experiment.sourceforge.net/promote-20050917/libs/ type_traits/test/promote_enum_test.cpp Alexander requests a fast-track review. //////////////////////////////////////////////////////////////////// 4) Libraries under development //////////////////////////////////////////////////////////////////// Property Tree Author - Marcin Kalicinski Download: Boost Sandbox Vault (http://boost-consulting.com/vault/) property_tree_rev3.zip Please let us know of any libraries you are currently developing that you intend to submit for review. Tom Brinkman Ronald Garcia Boost Review Wizards

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Other Pimpl implementation
by Peter Kümmel 19 Jan '06

19 Jan '06

Hello, maybe you are interested in a other Pimpl implementation which differs from pimpl_ptr in some points. Here a short overview: - you could declare a pimpl or inherit a pimpl (usage: pimpl->foo()) - you could also declare/inherit a rimpl (reference to implementation, usage rimpl.foo()) - you could use different smart pointer as pimpl which is adjusted by a policy, it's a little bit like a templated pimpl_ptr - there are more convenient typedefs - no lazy creation Example headers: ------------------------ //declare a Pimpl: class A { public: A(); void foo(); private: Pimpl<A>::Type d; }; ---------------------- //inherit a Pimpl: class B : private Pimpl<B>::Owner { public: B(); void foo(); }; ------------------------ //declare a Rimpl class C { public: C(); void foo(); private: Rimpl<C>::Init rinit; Rimpl<C>::Type d; }; ------------------------ //inherit a Rimpl: class D : private Rimpl<D>::Owner { public: D(); void foo(); }; The code is at the moment in the loki-lib cvs at sourceforge. If you are interested I could also send the files. Cheers, Peter

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patches status
by Marshall Clow 19 Jan '06

19 Jan '06

Here's a new report this week. These are the submitted patches that are waiting to be integrated/rejected/whatever. A bunch of these have been cleaned up in the last couple of weeks. Let's see if we can get this list down to zero! As always, if you see one that is mis-assigned, or you think that one marked "nobody" is right for you, please don't hesitate to jump in. ;-) Thank you for your cooperation! Patches per assignee: Beman Dawes 2 Joel de guzman (djowel) 1 Robert Ramey 1 Samuel Kremp 1 Ronald Garcia 1 nobody 1 Here are the currently submitted patches, sorted by assignee. Assignee: beman_dawes <http://sourceforge.net/users/beman_dawes/> Summary: name injection before definition Bug #: 1002538 <http://sourceforge.net/tracker/index.php?func=detail&aid=1002538&group_id=7…> Assignee: beman_dawes <http://sourceforge.net/users/beman_dawes/> Summary: patch for boost::filesystem Bug #: 1157160 <http://sourceforge.net/tracker/index.php?func=detail&aid=1157160&group_id=7…> Assignee: djowel <http://sourceforge.net/users/djowel/> Summary: spirit/symbols.ipp pragma warning fix Bug #: 1273960 <http://sourceforge.net/tracker/index.php?func=detail&aid=1273960&group_id=7…> Assignee: nobody Summary: Boost.Jam Compile Fix Bug #: 865533 <http://sourceforge.net/tracker/index.php?func=detail&aid=865533&group_id=75…> Assignee: ramey <http://sourceforge.net/users/ramey/> Summary: Boost.Serialization for std::bitset Bug #: 1029258 <http://sourceforge.net/tracker/index.php?func=detail&aid=1029258&group_id=7…> Assignee: rgarcia <http://sourceforge.net/users/rgarcia/> Summary: [concept_check.hpp] remove unused variable warning in msvc Bug #: 1388901 <http://sourceforge.net/tracker/index.php?func=detail&aid=1388901&group_id=7…> Assignee: samuel_k <http://sourceforge.net/users/samuel_k/> Summary: a simple patch about boost::format (for MSVC7.1) Bug #: 1202693 <http://sourceforge.net/tracker/index.php?func=detail&aid=1202693&group_id=7…> -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

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