February 2007 - Boost-announce

[Review][Bimap] Bimap review extended until March 2nd
by Ion Gaztañaga 22 Feb '07

22 Feb '07

Hi to all, Bimap review has been extended until March 2nd. I encourage all boosters to give a try to this great library. The links are: Start reading the documentation here: http://tinyurl.com/y95qng And download the library here: http://boost-consulting.com/vault/index.php?&directory=Containers Regards, Ion

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[boost] [Review results] Accumulators accepted
by John Phillips 19 Feb '07

19 Feb '07

The accumulator library submitted by Eric Niebler has been accepted into boost. Thanks, once again to all of the people who contributed to the development of the library, to everyone who contributed to the review, and to Eric for a fine submission. During the review, Eric and some of the reviewers had a useful discussion about issues for the library, and possible improvements. A condensed version of the outcomes from that discussion is included below. Also, in perusing the archives for other comments about the library, I found a couple of other issues that were discussed. I have included them below, as well. In many cases, Eric acknowledged issues and committed to a fix during the review. Those issues are included below, along with the current state of some of the more open ended discussions to provide easy reference for all interested parties. For my own organizational convenience, I have numbered the entries below. This does not indicate relative importance. 1) Prior to the review it was asked why the function that returns a histogram is called the density. Little was done at the time, as Eric suggested it should be addressed during the review. As far as I can see, it was not brought back up during the review process. This should be examined to make sure that density is the best name for the function, and changed if needed. 2) There are a number of variant implementations of some statistical functions. The documentation should clearly indicate which variants focus on quick and dirty implementations, and which provide more numeric stability. Eric has stated that this will be addressed in the revisions of the documentation. 3) The question was asked whether or not it is feasible to provide outlier rejection for some or all of the accumulators. I can find no further discussion of this question in the review, however, since this is a very important statistical technique it would be a good feature to investigate for future addition. 4) Michael Stevens expressed interest in a form of the variance that accumulates the differences squared iteratively and divides the result by n. I saw no direct response, but this is basically what the immediate_variance does. 5) Interest was expressed in making the compensated sum the default version of the sum. It could be supplimented by the quick and dirty version as an alternative. However, since there are reports that many optimizing compilers turn the compensated sum algorithm into the same compiled code as the simple sum, tests should be done to see if there is any real gain before the modification. 6) There are a number of broken links in the quickbook docs. This has been acknowledged and is in line for a fix. 7) Steven Watanabe suggested changing the structure to move away from the fusion vector dependence. After discussion it appears that fusion cons,. may be a better choice. However there may be a use case for the original library that precipitated the choice of fusion vector. This should be checked, and if Steven's idea holds up under scrutiny, it should be implemented. 8) There is a request that the user guide specifies which header each component is in. This has been acknowledged and is in line for a fix. 9) The macro BOOST_PARAMETER_NESTED_KEYWORD has no description in the docs. This has been acknowledged and is in line for a fix. 10) There were a number of requests for improvements to the reference manual, ranging from wording changes to a reorganization that reflects class structure instead of header structure. In some cases, these improvements are direct, and they are in line for fixes. In other cases there is currently no known way to do it with the boost tool chain. Eric, and many of the other members of boost would greatly appreciate anyone who has ideas and time to fix the harder problems. 11) There was a suggestion that the documentation could mention the TR1 reference_wrapper as a future solution to the accumulator_set_wrapper issues, and the implementation could be changed once there is a boost accepted implementation of the reference_wrapper. My impression was that I was not the only person who didn't realize that it could solve that problem. 12) Functions that allow a range of values to be pushed into an accumulator set all at once should be added. This could include forms that take begin and end iterators and forms that take a sequence. Eric agreed that this is a good idea. 13) Paul Bristow mentioned that the kurtosis has a confusing naming history. What the docs refer to as the kurtosis would better be called the "kurtosis excess." His suggestion was that a name change be considered and that the docs be modified to acknowledge the confusion whether the name is changed or not. Eric agreed with this suggestion. 14) Accessors for the standard deviation, the unbiased variance and the unbiased (N-1) standard deviation were requested. The fact that John Maddock fell into the trap of miscalculating the standard deviation shows that even experts can make mistakes when converting from the variance. Thus, it is a good idea for inclusion. Eric said he is interested, and he would also welcome submissions that provide these functions. 15) The docs mention "Even the extractors can accept named parameters. In a bit, we'll see a situation where that is useful," but there is no later mention. Eric has an example he intended that to refer to, but forgot to include it in the last edition of the docs. He intends to fix that. 16) The ability to "reset" and accumulator was requested. Eric pointed out that it is quite possible to make accumulators with reset methods. He also pointed out that it might be desirable to reset accumulator_sets, but this could also pose a problem. It is not clear what should happen if one of the accumulators used by an accumulator set does not have a reset method. Further thought should be given to this for possible inclusion in a later revision. 17) Autocorrelation for accumulator_sets should be explored. Matthias already plans to do this in the coming year for possible inclusion in a later revision. 18) The documentation on what to expect when one accumulator is dropped while a second accumulator that depends on the first is not dropped should be clarified. Careful thought on this may lead to a change in current behavior. 19) There is a request that the docs state more clearly what happens when more than one accumulator maps to the same feature. Eric plans to include this in documentation revisions. 20) It is not currently possible to combine accumulators. In some very common use cases, this would be an important feature. However, not all accumulators can be combined in any sensible way. A solution to this will require some study and design work, but it is a valuable addition for a future revision. One possible solution is to have a compile time check to see if the accumulators are combinable. 21) While finding newer/faster/more robust algorithms is not a bad thing, the focus of this review has been the interfaces. If the interfaces are good, improved algorithms can be worked in later. There is some minimum standard for performance, but it is not the focal point or the submission. 22) Javier and Hans submitted lists of documentation corrections that Eric acknowledged and plans to fix. 23) It is agreed that there is a need for a more gentle and thorough getting started document. This should include some compelling examples that show why this is a good design decision. 24) More of the formulas should be available in the documentation. Eric requested volunteers to make some formulas into LaTeX, and I have already contacted him to do so. 25) The docs for how to incorporate new features should be improved. This can be helped tremendously if the people who had problems doing this would send Eric descriptions of where they had problems with the docs and the process. Thanks again to everyone for your time and work. Any problems or misrepresentations in the above list are purely my fault, and I apologize for them. John _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/ listinfo.cgi/boost

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BoostCon 2007 update
by David Abrahams 19 Feb '07

19 Feb '07

The following message is a courtesy copy of an article that has been posted to gmane.comp.lib.boost.user,gmane.comp.lib.boost.devel,gmane.comp.lib.boost.interest as well. A couple of quick items: 1. The conference format has changed. For many practical reasons, the "two 3-day tracks with one day of overlap on Wednesday" format proved unworkable. Among those: * Many (most) sessions don't fall neatly into the library-user/library-developer track distinction. We see this as a good thing, as it means we have more material that's of broad interest. * It made the hotel reservation pattern very difficult; we were afraid many people would be shut out of rooms at the conference hotel and also that the hotel would not be able sell the entire reserved room block, which could cost the (non-profit) conference a lot of money, as we had to agree to be liable for unsold room nights. Instead, we're running two tracks concurrently all week. We thought attendees should be prepared for that change. 2. We expect the new boostcon website will go live and registration for the conference will open in the next couple of days. We're just clearing away a few final details. In the meantime, the existing http://www.boostcon.com has the old information. Regards, and see you at BoostCon, -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Re: [Boost-announce] [bimap] URL Correction: Review of the Bimap library begins today Feb 15
by Ion Gaztañaga 15 Feb '07

15 Feb '07

Hello everyone again: I'm resending this because the first URL was not correct. The other URLs were correct, so to sum up:: The library can be downloaded from Boost.Vault/Containers: URL: http://www.boost-consulting.com/vault/index.php?directory=Containers Tiny URL: http://tinyurl.com/ysfclr Online documentation and the documentation package can be found here: http://tinyurl.com/y95qng Sorry for the noise, Ion

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[bimap] Review of the Bimap library begins today Feb 15
by Ion Gaztañaga 15 Feb '07

15 Feb '07

Hello everyone, The review of the proposed Boost Bimap library written by Matias Capeletto starts today (February 15th, 2007) and ends after 10 days (February 25, 2007). Documentation for the library can be found online here: http://tinyurl.com/e2os3 The library can be downloaded from Boost.Vault/Containers: URL: http://www.boost-consulting.com/vault/index.php?directory=Containers Tiny URL: http://tinyurl.com/ysfclr Online documentation and the documentation package can be found here: http://tinyurl.com/y95qng --------------------------------------------------- Context: The library has been developed by Matias Capeletto with the mentoring of Joaquín M López Muñoz in the context of the Google SoC 2006. You can find more information about SoC projects here: http://code.google.com/soc/boost/about.html You can read an overview of Boost participation in Google Summer of Code 2006 written by Joaquín M López Muñoz here: http://boost.org/more/boost_soc_06_overview.html --------------------------------------------------- About the library: With Boost.Bimap you can create associative containers in which both types can be used as key. A bimap<X,Y> can be thought of as a combination of a std::map<X,Y> and a std::map<Y,X>. The learning curve of bimap is almost flat if you know how to use standard containers. A great deal of effort has been put into mapping the naming scheme of the STL in Boost.Bimap. The library is designed to match the common STL containers. Boost.Bimap offers also advanced features: -> Boost.Bimap offers much more than just a one-to-one ordered unique bidirectional map. It is possible to control the set type of each side of the relationship that the bimap represents, giving one-to-many containers, hashed bidirectional containers and others that may be more suitable to the the task at hand. -> The types of a bimap can be tagged so that each side is accessible by something closer to the problem than left and right. This leads to more readable, self-documenting code. -> The extended mapping framework allows to disable a view of a bimap, including the standard mapping containers as a particular case. Bimap has been tested in the following platforms: GCC 3.4/Linux GCC 4.0/Linux, Mac VS 7.1/Windows VS 8.0/Windows ICC 7.1/Windows ICC 8.0/Windows --------------------------------------------------- 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? Ion Gaztañaga Review Manager

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Review Managers Needed
by Tom Brinkman 07 Feb '07

07 Feb '07

We need volunteer review managers for most of the libraries in the review queue. If your interested, let us know. Preferably, you would have a background in the problem domain, but no association with the library and a contributer to the boost mailing list. The review schedule is available here: http://www.boost.org/more/formal_review_schedule.html . You can read the "review manager" requirements at the following link: http://www.boost.org/more/formal_review_process.htm Most of the libraries are located at the Boost Sandbox Vault, located here: http://boost-consulting.com/vault/ Maintainers of the Review Queue: Ronald Garcia (garcia (at) cs.indiana.edu) Tom Brinkman (reportbase (at) gmail.com) If there is any errors or ommisions in this report, please send them to Ron or Tom. Here is a summary of the libraries that are in the queue. ------------------------------------- Library: Exception Author: Emil Dotchevski Location: http://www.revergestudios.com/boost-exception/boost-exception.zip Review Manager: Needed Date: Needed Summary: The purpose of Boost Exception is to free designers of exception classes from having to consider what data needs to be stored in exception objects in order for the catch site to be able to make sense of what went wrong. When Boost Exception is used, arbitrary values can be stored in any exception. This can be done directly in the throw-expression, or at a later time as the exception object propagates up the call stack. The ability to add data to any exception object after it has been thrown is important, because often some of the information needed to handle an exception is unavailable at the time of the throw. ----------------------------------------- Library: Bimap Author: Matias Capeletto Location: Boost Sandbox Vault Review Manager: Ion Gaztañaga Date: February 15 2007- February 25, 2007 Summary: With Boost.Bimap you can create associative containers where both types can be used as key. You can think a `bimap<X,Y>` as a merge of a `std::map<X,Y>` and a `std::map<Y,X>`. The learning curve of bimap is almost zero if you know how to use standard containers. A big effort was put in mapping the naming scheme of the STL in Boost.Bimap. The library is designed to match the STL common containers. ----------------------------------------- Library: Globally Unique Identifier Author: Andy Tompkins Location: Boost Sandbox Vault Review Manager: Needed Date: Needed Summary: A guid, or globally unique identifier, is an identifier standard used in many disciplines including computer networks, distributed computing, and databases. They can be used to tag objects with very short lifetimes, to reliably identify very persistent objects across a network. An attractive feature of guids is their relative small size, of 128-bits, compared to alternatives. Also the creation of guids does not require a centralized authority. ----------------------------------------- Library: Intrusive Containers Author: Ion Gaztañaga Location: Boost Sandbox Vault Review Manager: Joaquín Mª López Muñoz Date: March 1, 2007 - March 10, 2007 Summary: 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. ----------------------------------------- Library: Scope Exit Author: Alexander Nasonov Location: Boost Sandbox Vault Review Manager: Needed Date: Needed Summary: The scope-exit-arg-pp-seq is Boot.Preprocessor sequence of identifiers that can be used inside scope-exit-body. The direct-declarator is declarator-id followed by optional argument of type boost::scope_exit_group (inside brackets or after the equal sign). This construct executes scope-exit-body at the close of the current scope. ----------------------------------------- Library: Finite State Machines Author: Andrey Semashev Location: Boost Sandbox Vault Review Manager: Needed Date: Needed Summary: The Boost.FSM library is an implementation of FSM (stands for Finite State Machine) programming concept. There are many cases when a developer would like to distinguish the behavior of a given object depending on some conditions or its internal state. For example, when making software to control an underground charging tourniquiet a programmer would like to separate states in which the tourniquiet may persist: an idle state, when the device awaits for another passenger that would like to pass; a processing state, when the passenger have come and put his ticket into the device; and the passing state, when the tourniquiet lets the passenger pass through. In fact, each state describes different reaction of the machine at the same events (a passenger may only pass after paying for ticket). Obviously, the tourniquiet have to be able to change its internal state in order to function properly, this is called state switching or transitions between states (or just transitions for short). ----------------------------------- Library: Statistical Distributions Author: John Maddock Location: Boost Sandbox Vault (math-toolkit) Review Manager: Needed Date: Needed Summary: Provides many of the tools required to implement mathematical special functions: hopefully the presence of these will encourage other authors to contribute more special function implementations in the future. There are helpers for the evaluation of infinite series, continued fractions and rational approximations. There is a fairly comprehensive set of root finding and function minimisation algorithms: both with and without derivative support. A Remez algorithm implementation allows for the locating of minimax rational approximations. There are also (experimental) classes for the manipulation of polynomials, for testing a special function against tabulated test data, and for the rapid generation of test data and/or data for output to an external graphing application. ----------------------------------- Library: Floating Point Utilities Author: Johan Råde Location: Boost Sandbox Vault http://boost-consulting.com/vault/index.php?directory=Math%20-%20Numerics Review Manager: Needed Date: Needed Summary: Proposed Additions to the Boost Math Library <boost/math/fpclassify.hpp> Functions for floating point number classification: fpclassify, isfinite, isinf, isnan, isnormal. Follows TR1. <boost/math/signbit.hpp> Functions for floating point number sign bit access and modification: signbit, copysign, changesign. Follows TR1. <boost/math/nonfinite_num_facets.hpp> Facets that parse and format infinity and NaN according to the C99 standard. Used for portable handling of infinity and NaN in text streams. ----------------------------------- Library: mcs::units Author: Matthias Schabel Location: Boost Sandbox Vault http://www.boost-consulting.org/vault/ (units) Review Manager: Needed Date: Needed Summary: mcs::units is a library providing zero-runtime overhead dimensional analysis for unit and quantity calculations. It provides support for 1) unit systems comprised of arbitrary sets of base units 2) arbitrary user-defined value types 3) support for heterogenous operator algebras (i.e. Z op(X,Y)) 4) support for basic outputting of quantities 5) optional support for implicit unit conversions It does not support 1) runtime units or quantities 2) input or parsing of quantities ----------------------------------- Library: Switch Author: Steven Watanabe Location: Boost Sandbox Vault http://tinyurl.com/yvssgx Review Manager: Needed Date: Needed Summary: Needed

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