April 2011 - Boost - lists.preview.boost.org

boost-test, why is there no DOUBLES_EQUAL?
by Sebastian Nowozin 31 May '11

31 May '11

Hello, I am a regular user of the boost test library, having used CPPunit before. I miss the following macro: BOOST_CHECK_DOUBLES_EQUAL(first, second, absolute_tolerance); which would check whether "std::fabs(first-second) <= absolute_tolerance" is true. It seems the boost test library does not support it, and instead forces/encourages users to use BOOST_CHECK_CLOSE(first, second, percent_relative_tolerance); The above macro does not really make sense in my application, I really need to check for absolute tolerances, irrespectively of the magnitude of the numbers. CPPunit has this feature as DOUBLES_EQUAL. Would you consider adding this? Thanks, Sebastian

9 16

Re: [boost] [date_time] Time zone improvements
by Rutger ter Borg 25 May '11

25 May '11

Jeff Garland wrote: > Very cool :-) One question -- is there a portable solution where a user > could deploy a files onto a Windows system or is it a Unix only solution? > I'm fine with incorporating a *nix only solution because what your > suggesting will be a nice solution for *nix platforms, but it will need to > be clear that it's not portable. I don't see why it wouldn't be possible to deploy the (big-endian) binary files to any platform. Getting it into this binary form (using zone info compiler zic) may be harder to do cross-platform, but cygwin may help here. [snip] > As the primary maintainer of Boost date-time I can say with certainty that > there is interest in this functionality -- it's long been on my todo list > and I haven't had time to get to it. You can email me privately and we > can discuss all the details of how to get your code incorporated. I'll do! Regards, Rutger

5 9

[Review] Type Traits Extension by Frederic Bron - Review summary and decision
by Joel Falcou 23 May '11

23 May '11

Hello all, Frederic Bron's type traits extension proposal review ended up last week. In so far, we received SEVEN reviews which are all voting YES for the inclusion of Type Traits extension in Boost. So the result is that the Type Traits Extension is ACCEPTED into Boost. Suggestions include: - some clean-up in the implementation like "Renam[ing] the detail classes inside the specific namespace without using number, i.e. with a clear meaning. The use of tag, tag 2 could be renamed check_pass, check_fail or something like that." - Sensibility on cv-ref qualifiers in traits call is important. This is being addressed by Frederic. - Frederic is OK to keep the detection of void as a valid return type by using some dont_check type as default. - small comprehensive example of some of the traits like a "maybe_print function, which prints a value if the appropriate operator<< ostream overload exists, else prints "<NOT PRINTABLE>". [...] a small example like this would show a practical use of the library, and how to make use of enable_if, or some other overload method." - The main recurring suggestions found was the choice of name for the operator traits with respect to the standard naming, naming in proto and other boost libraries. This topic is still hot and alive. An alternative to the naming scheme consensus was proposed in the form of alias of commonly used operator traits. This issue is I think beyond bikeshed-color argumentation and I think it is a good point if Frederic could step up and provide a definite and rationalized answer to this point. The current status is : * the namespace options is out casue the standard didnt choose this way; * Frederic and a few other seems to favor the proto naming scheme (more or less the negate issue and the pre/post operator) * the question of a common prefix is still open * the std:: like naming seems limited as not all operators are there. Thanks to all reviewers and people participating to the discussions. Thanks to Frederic for his work.

18 67

Boost.Log status
by Vicente BOTET 23 May '11

23 May '11

Hi, what is going on Boost.Log? The library was accepted provisionally on March 2010 * Log - accepted provisionally March 2010; author: Andrey Semashev. Best, Vicente

7 18

Boost statechart viewer
by Petr Šilhavík 20 May '11

20 May '11

Dear Boost-Statechart developers and users, I would like to ask you to try the tool that I am developing in my bachelor thesis and give me your opinion about it. The tool is able to visualize state machines that use Boost-Statechart library. It uses Clang and LLVM *(version 2.9)* for producing the output files that can be visualized using dot. Now it can work with states (not the orthogonal states), transitions and custom reactions. You can find more information about it on the web page of this project where you can also download the source codes and see some examples of the output pictures. http://rtime.felk.cvut.cz/statechart-viewer/ I am looking forward to your answers. Best regards Petr Silhavik

4 11

[local] this_ or _this?
by Lorenzo Caminiti 19 May '11

19 May '11

Hello all, Boost.Local uses a special name `this_` to access the object `this` bound from the enclosing scope. Shall this name be `this_` or `_this` according to Boost practices? struct c { void g(int x) { ... } void f() { void BOOST_LOCAL_FUNCTION_PARAMS( (int x) (bind this) ) { this_->g(x); // <<<<<<<<< Shall this be `_this->g(x);` instead? ... } BOOST_LOCAL_FUNCTIO_NAME(l) ... } ... }; In particular, some library uses _ postfix for statements like mpl::if_ (not mpl::_if) while other uses _ prefix for variables like phoenix::local_names::_f (not local_names::f_). Thanks a lot. -- Lorenzo

12 21

[boostcon][proto] Suggestion for LIAW session: fixed-point numbers
by Ravi 19 May '11

19 May '11

Hi, Are there any proto-based ideas for the library-in-a-week sessions? If not, would building a fixed-point data type be of interest? The domain is narrow enough that something useful can be accomplished in 4 sessions, but of large enough scope to present opportunities for exploring proto in depth. A fairly simple design follows representing a number: fixed_number<int width, int ulp, // 2^{ulp} is the smallest increment possible bool signed, template assigner<first, last, signed> > 'assigner' handles rounding/truncation/wrapping/etc when assigning another number (floating-point or fixed-point) to the current one. Internally, each fixed-point number would be represented by a boost::uint64_t or a boost::int64_t (limiting the maximum precision allowed). As an example, fixed_number<5, -3, false> would represent a data type that would go from 0 to 3.875 in steps of 0.125. Proto would be used for creating all arithmetic operations since the return type of a+b could be different from the type of either a or b. A bonus would involve getting the fixed-point data type to play well with std::complex (and, yes, I am aware that std::complex is not designed to work with anything other than double and float, and will require specialization in the std namespace). If there is sufficient interest, I could even provide a starting point with +,-,* implemented; / would take more time. The design above is intended as a starting point for discussion and I am most definitely not wedded to it. I am a tyro when it comes to proto, and hence would need someone with more proto expertise to guide the discussion. Regards, Ravi

8 24

Conversion/Enums/Opaque request for interest
by Vicente BOTET 16 May '11

16 May '11

Hi, Lastly I've been working on 3 Boost libraries proposals. * Boost.Conversion (https://svn.boost.org/svn/boost/sandbox/conversion/libs/conversion_ext/doc/…) * Boost.Enums (https://svn.boost.org/svn/boost/sandbox/enums/libs/enums/doc/html/index.html) * Boost.Opaque (https://svn.boost.org/svn/boost/sandbox/opaque/libs/opaque/doc/html/index.h…) Boost.Conversion manages with generic explicit conversion between unrelated types. The template function convert_to allows to convert a source type to a target type, using argument dependent lookup (ADL) to select a specialized convert_to function if available. If no specialized convert_to function is available, boost::conversion::convert_to is used. Boost.Enums intends to provide a partial solution to the scoped enums problem ensuring a portable solution compatible with compilers supporting natively scoped enums or not. In addition provides a framework to view enumerations as ordinal types so we can define some specific and efficient enum containers. Boost.Enums is composed of the following parts: * Scoped enums * Ordinal enums * Enum containers * MPL enums * String <-> Enum conversions Boost.Opaque intends to provide a library partial solution to "opaque typedefs". Boost.Opaque provides: * a generic mixin class hierarchy which can be specialized by the user to make new opaque classes. * a generic class hierarchy which can be instantiated by the user to make new opaque typedefs. * a meta-mixin concept that allows to compose in a easy way several aspects of a class in an orthogonal way. * a considerable number of meta-mixins that helps defining new types from an underlying type * Some helper macros that can reduce the declaration of a new opaque type to a single line, emulating the language-based approach. Boost.Opaque and Boost.Enums depend in some degree on Boost.Conversion. These are quite basic libraries that any of you could find useful (or not) and that are not associated to a complex domain, so any of you could have an opinion without spending too much time. Please follow the above links to have a better idea of the motivation of these libraries. Before continuing completing the design, docs and tests of these libraries I would like to know if there is an interest on these libraries and if you have any suggestion on how to improve them, you see something missing or that should be removed. This will help me a lot to concentrate my efforts on the library that reveals more interest. Any comment will really be appreciated. Thanks, Vicente

7 10

[multi_array] Is there interest for an [index_list] library?
by Pierre-Andre Noel 13 May '11

13 May '11

(This email has earlier been sent to the wrong list. Thanks to Steven Watanabe for pointing that out.) Dear all, I would like to gauge the interest of the community in a library that can serve 1) as a complement to Boost.MultiArray and 2) as an alternative to Boost.MultiArray. For the first type of use, an example of the candidate library's capabilities is that it makes available a special iterator "it" that allows to browse all the elements of a MultiArray "m". This special iterator has an it.indices() members that returns a "list" Collection of indices (i.e. an IndexList) such that "m(list)" and "*it" are the same elements. This can be useful for functions whose effect on an element of "m" depends on where this element is situated in "m". The second way to use the candidate library is as an alternative to Boost.MultiArray of dynamically chosen (execution time) dimensionality. Moreover, the elements do not necessarily need to be arranged in a multi-dimensional "box", as is the case in a MultiArray. For example, a "simplex" organization of the elements is already implemented. If you are interested to know more, I strongly suggest you to take a look at the example file in sandbox/index_list/libs/index_list/examples.cpp . The library itself is in sandbox/index_list/boost and a readme file (with some details concerning concepts and "priorities") is in sandbox/index_list/libs/README . An automatically generated (Doxygen) documentation is located in sandbox/index_list/libs/index_list/doc/index.html . Sadly, there is no "real" documentation for now. Many thanks for your time. Sincerely, Pierre-André Noël

5 11

[local] Help for the Alternatives section
by Lorenzo Caminiti 12 May '11

12 May '11

Hello all, I am updating Boost.Local docs and I could use a some help in getting the Alternatives section right http://svn.boost.org/svn/boost/sandbox/local/libs/local/doc/html/boost_loca… . How can I program the following code (its local function and `factor` constant binding) using Boost.Phoenix, Boost.Lambda, and C++0x lambda functions? If you know, can you please reply with the actual code? #include <boost/local/function.hpp> #include <iostream> #include <vector> #include <algorithm> int main() { double sum = 0.0; int factor = 10; void BOOST_LOCAL_FUNCTION_PARAMS(double num, // Variable `factor` bound as constant. bind& sum, const bind& factor) { sum += factor * num; std::cout << "Summed: " << sum << std::endl; } BOOST_LOCAL_FUNCTION_NAME(add) std::vector<double> v(3); v[0] = 1.0; v[1] = 2.0; v[2] = 3.0; // Local function `add` passed as template parameter. std::for_each(v.begin(), v.end(), add); return 0; } Thank you very much! -- Lorenzo

14 82

[provocative] Whom did the SFC pay to list boost developers as a whole in "Current Member Projects"?
by Alexander Terekhov 08 May '11

08 May '11

http://sfconservancy.org/members/current/ (Current Member Projects) "Boost provides free peer-reviewed portable C++ source libraries. Boost emphasizes libraries that work well with the C++ Standard Library. Boost libraries are intended to be widely useful, and usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. Boost aims to establish existing practice and provide reference implementations so that Boost libraries are suitable for eventual standardization. Ten Boost libraries are already included in the C++ Standards Committee's Library Technical Report ( TR1) as a step toward becoming part of a future C++ Standard. More Boost libraries are proposed for the upcoming TR2." The context: (pacer) 03/23/2011 192 ENDORSED LETTER addressed to Judge Shira A. Scheindlin from David Leichtman dated 3/23/2011 re: Requesting that the Reply and Kuhn Declaration be stricken, or in the alternative, that the Court consider Best Buy's responses to these new theories and arguments. ENDORSEMENT: Defendant's request is granted. The Court will consider Best Buy's response to the new issues raised in Plaintiffs' Reply, as set forth in this letter. So Ordered. (Signed by Judge Shira A. Scheindlin on 3/23/2011) (jpo) (Entered: 03/23/2011) 04/14/2011 193 OPINION AND ORDER. For the reasons in this opinion and order, plaintiffs' motion to join WD is denied. The Clerk of the Court is directed to close this motion (Docket No. 133). (Signed by Judge Shira A. Scheindlin on 4/14/2011) (rjm) (Entered: 04/15/2011) 04/26/2011 194 ENDORSED LETTER addressed to Judge Shira A. Scheindlin from Emmett J. McMahon, dated 4/25/2011, re: Counsel for the defendant Best Buy Co., writes to request a pre-motion conference regarding a motion to strike Plaintiffs' claim for "actual damages and any additional profits of [Best Buy] incurred as the result of infringement." ENDORSEMENT: Request granted. A premotion conference will be held on May 6 at 2:30. So Ordered. (Pre-Motion Conference set for 5/6/2011 at 02:30 PM before Judge Shira A. Scheindlin) (Signed by Judge Shira A. Scheindlin on 4/25/2011) (lnl) (Entered: 04/26/2011) (details) http://www.terekhov.de/192.pdf http://www.terekhov.de/194.pdf Suggestion: Please remove boost from http://sfconservancy.org/members TIA. regards, alexander.

9 22

[PBGL] Distributed adyacency_list memory allocation
by Cosimo Calabrese 06 May '11

06 May '11

Hi to all, I'm working on WinXP, VS2010, boost 1.46.1. I've writed this short program: //---------------------------------- #include <boost/graph/use_mpi.hpp> #include <boost/graph/distributed/mpi_process_group.hpp> #include <boost/graph/distributed/adjacency_list.hpp> using boost::graph::distributed::mpi_process_group; typedef boost::property<boost::vertex_distance_t, long, boost::property<boost::vertex_name_t, std::string > > vertex_prop; typedef boost::property<boost::edge_weight_t, long > edge_prop; typedef boost::adjacency_list< boost::vecS, boost::distributedS<mpi_process_group, boost::vecS>, boost::directedS, vertex_prop, edge_prop > Graph; typedef boost::graph_traits<Graph>::edge_descriptor EdgeDescriptor; typedef boost::graph_traits<Graph>::vertex_descriptor VertexDescriptor; int main(int argc, char* argv[]) { boost::mpi::environment env(argc,argv); Graph g( 10 ); return 0; } //---------------------------------- When I launch it, every process allocates about 1 GB of memory. Why it allocates all that memory? Is it normal? Is there any tuning to the PBGL framework that I must made? I use it on a 2-core machine, and the command that I use is: mpiexec -n 2 .\test.exe I've tried with openMPI 1.4.3 and Microsoft HPC Pack 2008, but it seems irrilevant. Thanks in advance, Cosimo Calabrese.

2 1

[xint] Formal Review Result
by Vladimir Prus 06 May '11

06 May '11

I apologize for the delay in producing the final summary and result of the Boost.Xint review, but here it is. Votes ===== YES: - Christian Henning - Steven Watanabe - Jarrad Waterloo - Edward Diener - Paul A. Bristow NO : - Mathias Gaunard - Joel Falcou - Anders Dalvander - Joachim Faulhaber - Phil Endecott - Domagoj Saric - Gordon Woodhull ("fraction of a vote") I might have missed somebody inside the 454 messages I have as result of the review, but the overall picture is clear -- the votes are split. High-level issues ================= - The claim that the library is "fast" is not necessary true. Phil has did some checking against hand-written assembler that don't look too good. - It is not clear whether the design allows for improving performance of fixed-size integers using specialization (again, see Phil's comments) - There were concerns about COW. In particular, it was very clearly stated that if COW is used, it should work fine in multi-threaded programs. - It was suggested to use ET. - Some folks suggested better separation between algorithms and data representation. Specific issues =============== - It was pointed out that "a + b + c" creates a pile of temporaries, and this can be improved without using ET. - Joachim's review raised a lot of valid points. Section 3 of his reviews in something that should be addressed, more or less entirely. Note that while we normally don't force specific coding style, some of formatting pointed out is simply unacceptable if this code is to be read by anybody. - 'Secure' flag is probably not so much of it. Future directions ================= I think that reviews by Phil and Joachim are most important in specying evolutionary directions for Boost.XInt. Chad made several comments about what he plans to do, in particular: - http://article.gmane.org/gmane.comp.lib.boost.devel/216935 Conclusion ========== I think there's no doubt that (i) this domain is important and (ii) Chad has put a lot of work into this library, producing several iterations. It was pointed out that we have many arbitrary-precision libraries skeletons all around Boost, and providing such a solid offering for review is a significant accomplishment. And it everybody learned a lot during the review. There was a couple of important meta-points raised during review -- whether review should focus on external interface only, and what is the scope of the library. Some reviewers argued that only external interface matters. However, it seems to me (as review manager), that concerns about internal design are valid, and may not be rejected offhand. After all, external interface of an integer library is more or less defined by mathematics, and internal design plays a key role in successfull evolution of the library. There was also heated discussion about the scope of the library, in particular support for fixed-width integers. I think that it's abstractly OK for this library to treat fixed-width integers as second-class citizens. However, I am having hard time determining the intended scope of the library. If I'm doing cryptography, would I really want to implement cryptography algorithms from the books with Boost.XInt, only to introduce bugs that are probably fixed in existing implementations (often, included in the OS). And if I'm really intent on doing that, I probably want raw performance, including a way to plug in optimized backends using SSE 2011, CUDA, and whatever fancy technology is there. If I'm doing general programming, then I'm most likely interested in not too big integers. They might be fixed-width 128-bit integers, or they might be something larger-than-64, but not necessary fixed. However, such integers are not the scope of the library, and they were found to have suboptimal performance. It is certainly possible to refine/define the scope, optimize everything for that scope, accomodate the proposals made during review, and obtain an excellent Boost library. However, there are some many suggestions, and so many planned redesigns and changes, that we need a second look at the library. Further, because of the global nature of the changes, it would be very hard to identify a specific subset that must be improved and then go through mini-review. For that reason, I've arrived at the the following result: Boost.Xint library is not accepted at this time. We'll be happy to have another full review of the library when the next version is ready. Thanks to Chad for the submission and for everybody who participated in the review! - Volodya -- Vladimir Prus Mentor Graphics +7 (812) 677-68-40

10 17

next version dates
by Andy Tompkins 05 May '11

05 May '11

Hi, Has it been decided the dates relevant to the next version? I have only looked here (http://www.boost.org/development/index.html) and didn't see anything. I'm not trying to change / hurry or delay anything. I just want to start moving some changes from trunk to release, but I work slowly and want to start closer to the beginning of a release, not closer to the end of one. Regards, Andy Tompkins.

6 12

Boost.Locale and the standard "message" facet
by Vicente BOTET 05 May '11

05 May '11

Hi, I was wondering how Boost.Locale is related to the standard message facet which is used to translate messages. Note that the facet interface work with integer identifiers avoiding all the issues raised by the get_text/translate functions provided by Boost.Locale. Is there any reason Boost.Locale could not follow the standard design? What are the advantages of the Boost.Locale design? Best, Vicente

4 6

[config] Macro BOOST_NO_NOEXCEPT is required
by Takaya Saito (SubaruG) 05 May '11

05 May '11

http://thread.gmane.org/gmane.comp.lib.boost.devel/214978 I think the macro BOOST_NO_NOEXCEPT ( or BOOST_NO_0X_NOEXCEPT ) is required soon. How's the status now?

5 7

[Block Pointer] make_block
by Phil Bouchard 04 May '11

04 May '11

Hi, I just disabled the constructor and the assignment operator having a raw pointers as a parameter and I added the make_block factory function. We can see it in action in the following example: https://svn.boost.org/svn/boost/sandbox/block_ptr/libs/smart_ptr/example/bl… Is it time for a review? -Phil

7 23

[atomic] Status?
by vicente.botet 04 May '11

04 May '11

Hi, There are some libraries that would prefer to be reviewed after Boost.Atomic is reviewed, otherwise them should move the library as an internal detail of the implementation. Could the people working on Boost.Atomic tell us what is the state of the library? Which platforms have been handled? Which part of the standard has been implemented? Could others having knowledge in assembler participate in this project? When we can expect the library to be ready for review? Best, Vicente

10 20

[Review] Boost.Convert library, new subversion URL
by Edward Diener 03 May '11

03 May '11

This is a reminder that formal review of the Boost.Convert library by Vladimir Batov starts today, April 23, and is scheduled to last through May 2. *************** * Its Purpose * *************** The library builds on the past boost::lexical_cast experience, then takes those conversion-related ideas further to suit better today's applications and programing needs. It still offers simple, minimal interface, familiar conversion behavior and additionally provides: * throwing and non-throwing conversion-failure behavior; * support for the default/fallback value to be returned when conversion fails; * two types of the conversion-failure check - basic/simple and better/safe; * formatting support based on the standard std::streams and std::stream-based manipulators (like std::hex, std::scientific, etc.); * support for different locales; * support for boost::range-compliant char and wchar_t-based containers; * no DefaultConstructibility requirement for the Target/Destination type; * consistent framework to uniformly incorporate any type-to-type conversions, extensibility and additional room to grow. With its present support for string-to-type and type-to-string conversions it is an essential tool for applications making extensive use of configuration or MS-Windows-Registry-style files or having to process/prepare considerable amounts of data in, say, XML, etc. More so, it is easily extendable to accommodate, specialize and uniformly deploy new user-defined type-to-type conversions. ******************* * Where to get it * ******************* Normally you can find Boost.Convert here: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-… However because the boostpro web site is having problems and will likely be down for the weekend, I have put the library into the Boost sandbox temporarily, since the Boost sandbox is up. So you can get the library, using Subversion, from https://svn.boost.org/svn/boost/sandbox/convert. This is exactly the same as the vault with the files unzipped. The HTML documentation is part of the distribution and can be found at libs/convert/index.html in the distribution above. ******************** * Writing a review * ******************** The reviews and all comments should be submitted to the developers list, and the email should have "[convert] Review" at the beginning of the subject line to make sure it's not missed. Please explicitly state in your review whether the library should be accepted. The general review checklist: - 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? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Edward Diener, Review Manager

12 19

Checking interest: reflectable types
by Noah Roberts 03 May '11

03 May '11

In my work I've developed a sort of reflection library for C++. There are still many problems to solve before it could near real reflection but I don't believe they are insoluble. It works much like fusion maps except that you can extend them through inheritance. In fact, my current implementation uses fusion to do its thing and with some minor changes to fusion::map it could provide the base. There is a boost.reflection proposal out there that is meant to work with boost.extension. This one is a bit different in that you're not additionally defining data; instead you declare your reflection as you declare your reflectable type through the instantiation of and inheritance from template metafunctions. It's primarily a static/compile-time kind of reflection but can be extended into runtime simply by making your field types a little smarter. Fields describe the data and provide access identifiers. Since they are general types that simply have to have an internal typedef you can attach whatever information is useful. We've done such things as attach valid value ranges, labels, etc... I currently use it do auto-construct property trees for user editing. I plan to use it for scripting/extension. I've had a look at boost.python and it looks like it would be possible, without too much difficulty, to automate python exposure of these types. A coworker with 0 experience in metaprogramming found it fairly easy to feed the types into a structure meant for a report design and printing library. This isn't a promise to actually do anything. I'm just gauging how much, if any interest there is to decide if I want to go to the trouble of hobby developing a publicly available and usable version.

4 11

[website] Suggestions
by Stephan T. Lavavej 02 May '11

02 May '11

It would be wonderful if: 1. On the main page, there was a direct link to the current version's documentation. Currently, you have to click Documentation, then "1.46.1 - Current Release". (Actually, I just noticed that a direct link does exist - Libraries under Welcome. I was hoping for a big blue button saying GET DOCS.) 2. There was a terse list of links to each library's documentation. The master list currently mentions 6 additional pieces of information for each library (Summary, Authors, First Release, Standard, Build, and Categories). That's nice, but it makes finding library X's documentation significantly more tedious than it has to be (I count 105 libraries in 1.46.1 - that's a lot of scrolling!). I suspect that even beginners don't need information other than the Summary 99% of the time. The current info should be preserved somewhere, but clicking on a release's documentation should bring up a terse list first. http://cid-e66e02dc83efb165.office.live.com/self.aspx/docs/boost.html is a horribly ugly preview of what I'm suggesting (because some libraries have long summaries, I've arbitrarily truncated them; ideally, each library would have a single-line summary at reasonable browser widths). 3. http://boost.org didn't redirect to http://www.boost.org . Even better, if the reverse happened ("Class B", according to http://no-www.org/faq.php ). Clearly, this is the most important issue of all. :-> Stephan T. Lavavej Visual C++ Libraries Developer

5 4

[locale] Review results for Boost.Locale library
by Chad Nelson 02 May '11

02 May '11

The formal review of Artyom Beilis' Boost.Locale library, originally scheduled to run from April 7th through the 16th and extended through the 22nd, is now finished. Fifteen people cast votes on it, ten for acceptance and five against. Though not overwhelming, the two-to-one majority clearly indicates the consensus of the list. As such: The Boost.Locale library IS ACCEPTED into Boost. The details follow, starting with the voters in favor, in the order their reviews were received: * John Bytheway * Steven Watanabe * Sebastian Redl * Fabio Fracassi ("possibly conditional") * Noah Roberts * Steve Bush * Volker Lukas * Paul A. Bristow * Matus Chochlik * Gevorg Voskanyan Those opposed: * Ryou Ezoe * Phil Endecott (but "borderline") * Edward Diener * Mathias Gaunard * Vincente BOTET ("count my vote as 1/2 or 1/4 vote") There was also an early off-list review from Darren Cook which did not include a vote, only listing issues. There was a great deal of discussion around the library, and a number of issues detailed. The major ones (and some less major ones that were repeated by several reviewers) are summarized below, along with the initials of the reviewer(s) who brought them up and Artyom's responses. Note that although I followed the discussions closely, these are only the issues brought up in the formal reviews themselves. * Issue: date_time interface uses enums for periods, which is error prone and inconsistent with other date/time libraries. (JB) * Response: Will be addressed. * Issue: Reference documentation needs more detail or some things not clear; some terms used in the documentation are not defined or are defined too briefly; can't find headers that items are defined in from the documentation. (JB, SW, FF, PE, ED, MC) * Response: Will be addressed. * Issue: There are no prev/next links in the documentation, or tutorial can't easily be navigated. (DC, JB, SR, FF, MC) * Response: Looking into it. * Issue: Few examples include output. (JB) * Response: Will be addressed. * Issue: No examples in Asian languages; the library may have design flaws that are not apparent without them. (DC) * Response: [Artyom has indicated to me (privately) that he's adding such examples. -- CN] * Issue: The translation system requires narrow-character tags, making it English-centric. (RE, ED) * Response: The library implements the most popular and most widely used message-catalog format. It is not perfect, but it is the best system currently available. There may be a work-around if you really must use wide-character languages under Windows. * Issue: Support for wchar_t/UTF-16 is unclear. (RE, ED) * Response: Wide characters are fully supported. * Issue: Doesn't support Win32 API as a backend. (RE) * Response: Misunderstanding, Win32 API backend is fully supported. * Issue: boost::locale::format is not compatible with boost::format. (FF, NR) * Response: boost::format is too limited for use in localization, and throws on any error, which means that a translator error could crash the program. * Issue: boost::locale::date_time is not compatible with boost::date_time. (FF) * Response: An unavoidable consequence of the differences between them, which are necessary due to support for locale independence and non-Gregorian calendars. * Issue: Boundary analysis is only available when using ICU. (FF) * Response: At present, only the ICU backend supports proper boundary analysis. * Issue: Little documentation on the toolchain needed to extract strings and translate them, or the versions required. (FF, NR) * Response: Will be addressed. * Issue: Concerns about relying on GPL/LGPL-licensed tools, or their availability on all platforms, or recommendations to write a Boost version of these tools. (NR) * Response: Reimplementing these is non-trivial and unnecessary; the licensing for these tools does not affect the programs developed with them. All are available for all platforms; will add explicit instructions for getting the latest versions for Windows. * Issue: Use of strings instead of symbols for language and encoding makes run-time errors that could be compile-time errors. The most common ones should be symbols. (PE) * Response: There are dozens of character encodings, and even more locales, and no way to determine which ones are the most common. Not all encodings are supported by all backends or OS configurations. Names ignore case and non-alphanumeric characters, which should minimize errors that could be generated from them. utf_to_utf transcoding will be added. * Issue: Error handling (in conversions) is very basic. (PE) * Response: An unavoidable limitation of the backends. * Issue: Code could use more commenting. (PE, VL) * Response: Noted, will be addressed in the future. * Issue: Some documentation phrasing is confusing, or could use a native English speaker's input. (SR, VL) * Response: Will be addressed as discovered. * Issue: There are no lists of valid language, country, encoding, or variant strings. (ED) * Response: Listed in standards ISO-639 and ISO-3166, which are referenced in the library's documentation. These standards are updated occasionally, and should be referred to directly for the latest information. * Issue: Only works on contiguous, entirely-in-memory strings. (MG) * Response: All current backends require this, and it satisfies the vast majority of use-cases. * Issue: Boundary analysis goes through the entire string and returns a vector of positions. (MG) * Response: Not perfect, but given the limitations of the existing backends, it is reasonable. * Issue: The library's interface is not generic enough, or independent enough of the libraries that it wraps. (VB) * Response: The interface is similar to that of every other i18n library, and should make as few assumptions as possible. It should not be changed. * Issue: The date-time code should be merged into Boost.DateTime. (VB) * Response: Date-time code is locale-dependent by its nature, and is more natural in Boost.Locale. Updating Boost.DateTime to do everything that Boost.Locale's library does would require a lot of work, and in all the time it has existed, only the Gregorian calendar has been implemented. There are Boost libraries that overlap others, so this is not a novelty. -- Chad Nelson Oak Circle Software, Inc. * * *

18 71

[BOOST CORE C++ Feature] The super or base keyword for C++
by Max Hölzer 02 May '11

02 May '11

Hello, i was wondering if it makes sens to add the well known super or base keyword to the C++ language in a generic way. Here I have a simple example on how it would make inherited base or super class overloaded function calls easier. Example 1: class A { public: virtual void print() { std::cout << "A" << std::endl; } }; class B : public A { public: virtual void print() { std::cout << "B" << std::endl; std::cout << "super call "; A::print(); } }; class C : public B { public: virtual void print() { std::cout << "C" << std::endl; std::cout << "super call "; B::print(); } }; int main(int argc, char* argv[]) { A a; B b; C c; a.print(); // Prints A b.print(); // Prints B and super call A c.print(); // Prints C and super call B super call A return 0; } Adding a template class superable would avoid one to write the explicit base or super class name. Example 2: namespace boost { template<typename T> class superable : public T { public: typedef T super; // C++ and java style typedef T base; // C# style }; } class A { public: virtual void print() { std::cout << "A" << std::endl; } }; class B : boost::superable<A> { public: virtual void print() { std::cout << "B" << std::endl; std::cout << "super call "; super::print(); // C++ and java style call } }; class C : boost::superable<B> { public: virtual void print() { std::cout << "C" << std::endl; std::cout << "super call "; base::print(); // C# style call } }; int main(int argc, char* argv[]) { A a; B b; C c; a.print(); // Prints A b.print(); // Prints B and super call A c.print(); // Prints C and super call B super call A return 0; } If somebody could add this to the core boost library, that would be great. Sincerely yours, Max

2 1

[filesystem] Decomposition of filenames beginning with period?
by Beman Dawes 01 May '11

01 May '11

Boost.Filesystem class path views filenames as being made up of a stem and an extension. My Windows Users directory includes files ".gitconfig" and ".netrc". The current class path implementation views these as having extensions of ".gitconfig" and ".netrc", respectively, and empty stems. To me, that's a bit counter intuitive. I guess I view filenames as always having stems, but extensions being optional. But I don't view that as a strong enough argument to change anything. Does anyone have a stronger argument than intuition for changing or retaining the current behavior? --Beman

13 20

Re : [Block Pointer] make_block
by Pierre Morcello 01 May '11

01 May '11

Hi Phil, >>> Phil Bouchard <philippe(a)fornux.com> wrote : >>> We can see it in action >>> in the following example: >>> https://svn.boost.org/svn/boost/sandbox/block_ptr/libs/smart_ptr/example/bl… A detail : I think you could improve your sample by replacing __FUNCTION__ by BOOST_CURRENT_FUNCTION (which is more portable), or by writing directly the name of the function. >>>Is it time for a review? I looked for automated tests in the sandbox directory (not examples) and I did not find any. Instead of doing "cout", you could use a class like that : class ForTests { static int counter; // incremented at each construction int id; // id = current value of the counter in the constructor static std::vector<int> destructionOrder; }; Each destruction pushes the id in the destructionOrder vector. Then at the end of the program you just need to compare the content of destructionOrder with what you should expect (and return 1 or 0). Also the same might be done for construction. Good job BTW, and good luck for the review, Pierre Morcello

2 4