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[function] timing trivia
by Matthew Hurd 12 Feb '04

12 Feb '04

Just a note to say thanks for boost::function ;-) Just completed some timings of the cost of a boost function call using a boost::function<void (void)> and a raw function pointer versus inlining the function's code directly into the source. For my circumstances (your mileage may vary): Calling via raw function pointer = 314 microseconds +/- 1 Calling via boost function variable = 328 microseconds +/- 1 Only 14 microseconds of difference. Nice work, I was expecting much more. Regards, Matt Hurd. Note: Optimised VC7.1 output, winXP 1a, Athlon 2800+ (2.09GHz)

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RE: [boost] Re: 1.31.0 regressions
by Rozental, Gennadiy 12 Feb '04

12 Feb '04

> One small addition to the regression presentation that would > help would be a view organized first by library, and then by > OS/compiler. Currently I have to click all over the place to > find the results for a single library. > > Cheers, > Jeremy Second that. Though it will require extra work. Gennadiy.

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<boost/pending/*.hpp> documentation, examples, and bugs.
by Cromwell Enage 12 Feb '04

12 Feb '04

I'm assuming "ground zero" here also means "square one" :) Preliminary documentation and an example program for <boost/pending/indirect_cmp.hpp>, <boost/pending/mutable_queue.hpp>, and <boost/pending/fibonacci_heap.hpp> can be found at: <http://groups.yahoo.com/group/boost/files/pending/> Bugs: The mutable_queue constructor that takes InputIterator arguments is push()-ing each element twice, because the the internal vector c is first initialized with the elements, then each push() in the while loop adds each element into c again. The example program demonstrates this. The fibonacci_heap fails at the first assert() during pop(). More to come! Cromwell Enage __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html

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VTL question (sorry if this is slightly off-topic)
by Matt Verona 12 Feb '04

12 Feb '04

Hello, I was reviewing the View Template Library (VTL) - see http://www.zib.de/weiser/vtl/ ... and have a few questions regarding Views as applied to STL Maps. I was also wondering if Boost was planning to eventually provide a VTL-like framework? I'm looking for a type of View that provides read-only access to an STL map, with only const iterators, but also provides limited insertion and removal access as well (as shown below): This new limited View-like map will only allow clients to iterate using const iterators, and also provides only one public insert(const key&) and one erase(const key&) method. These insert and erase member functions need to be implemented as "Template Method Functions", as follows: (see Design Patterns) * Note: these are shown using the latest SGI STL implementation (i.e., the _M_t.insert_unique and _M_t.erase calls) virtual bool preInsert(const value_type&) { return true; } pair<iterator, bool> insert(const value_type& x) { if(preInsert(x) { return _M_t.insert_unique(x); } return make_pair(end(), false); // make compiler happy } virtual bool preErase(const key_type&) { return true; } size_type erase(const key_type& x) { if(preErase(x) { return _M_t.erase(x); } return 0; // make compiler happy } The preInsert and preErase methods are virtual Hook Methods, and derived classes override these to add behavior to the (non-virtual) insert and erase functions.. Another nice addition to this map view would be a const _Tp& operator[](const key_type& k) const function, implemented something like this: const _Tp& operator[](const key_type& k) const { const_iterator i = lower_bound(k); if(i == end() || key_comp(k, (*i).first)) // if i->first is >= k throw SearchError(k); return (*i).second; } * Note: this simple implementation assumes that the key can be converted to a string in the constructor of the SearchError exception object. I have at least three Manager-like (Mediator) classes that can use this pattern (i.e., derived from this Map View class) as well as others that need a vector view with a similar filtered design... Thanks in advance, ~Matt Verona Houston, Texas USA

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RE: [boost] Re: 1.31.0 regressions
by Rozental, Gennadiy 12 Feb '04

12 Feb '04

> What about generating an email to the maintainers of the > corresponding library, which makes sure they will know about > a failed test ... :-) I do not mind. If it will only happened once - when test start failing. Or anytime test status changed. It may be convenient also to notify when kind of error test reports changed, but it's quite difficult to analyze in generic fashion. Gennadiy.

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RE: [boost] Boost Test Framework - log and report files
by Rozental, Gennadiy 12 Feb '04

12 Feb '04

> 1. I need to have the test log and report written to two > separate files in xml format. (It would be nice to have a DTD > of both xml formats) Ok. Will do. Will the schema work? < I did this by instructing the framework > with the command line argument: --output_format=XML. Now that > I had both the log and result report in XML format I needed > to create two file streams to redirect the output of them to > each their own file. This was easy to achieve with the log > using the set_log_stream method, but not so trivial with the > result report. Calling the singleton of the result report > before the test framework has initialized my code first calls > a null pointer crashing the test. How should this be done? > The documentation states that the interface of the > unit_test_result does not need to be used directly, but in my > case where I want a file stream instead of the std::err I > need to have access to the singleton and preferable in the > same place I set up the rest of my test suites. First of all why would you need to do anything? By default log goes to std::out and report goes to std::err. Also as you mentioned log output stream could be reset using set_log_stream method. This should be enough for your purposes As for report output stream it's actually unit_test_main who is responsible for setting specific stream and it not configurable at the moment. > 2. To achieve pt 1 I needed to edit unit_test_framework.hpp > (I think). I wanted to add support for my own command line > argument which would instruct the framework of the two files > I would like to create. So I thought it would be convenient > to use the reteive_framework_parameter method to retrieve my > custom command argument. Sadly enough I noticed that the > method doesn't return the value assigned to my argument > unless it is recognized. Is this fair? Yes. This is true. reteive_framework_parameter only strips parameters from command line that it knows about. The rest you are getting in init function. You could use any method to retrieve the value needed for you. Actually CLA support will be the first thing I am going to rework completely for next release. I think it should address your concern either. See mailing list for updates. > Daniel R. Kåsa > Gennadiy.

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any smart pointer alternative suggestions?
by Trey Jackson 12 Feb '04

12 Feb '04

All, I'm loving the shared_ptr class, however we have one issue that doesn't seem to be addressed by any of boost's smart pointers, and I'm looking for a work-around/alternative. Any help? The issue is that the smart pointers assume the pointer type to be 'T*', which is fine on a 32-bit system, but means that we get a near doubling of run-time size on our application when we move to a 64-bit application. As a result, we're using the standard technique to have a custom heap, and use our own 'pointers' into that heap that are smaller (typically 32-bits). But of course our ClassOnHeapPtr type does not match a 'ClassOnHeap *', so a boost::shared_ptr<ClassOnHeap> won't work. Are there any other libraries you boosters would recommend? thanks for any info... TJ -- Trey Jackson tjackson(a)ichips.intel.com "This is gonna cost me." -- Homer

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Passing value safely to functions
by Michael D. Borghardt 12 Feb '04

12 Feb '04

This started with looking at sign/unsigned interfaces and how to handle range problems. Now this looks to me to handle any numeric conversion problems. Comments, and criticisms welcome. #include <boost/numeric/cast.hpp> template<typename Target> class numeric_class { public: template<typename Source>numeric_class(numeric_class<Source> &s) { value_ = boost::numeric_cast<Target>(s); } template<typename Source>numeric_class(Source s) { value_ = boost::numeric_cast<Target>(s); } numeric_class(Target s) { value_ = s; } template <typename Resultant> operator Resultant() { return boost::numeric_cast<Resultant>(value_); } operator Target() { return value; } private: Target value_; }; void Bar(numeric_class<unsigned long> ul) { // we know that value in ul is in range if we get here } numeric_class<float> Foo(numeric_class<unsigned long> ul) { // we know that value in ul is in range if we get here return numeric_class<float>(ul); } int main () { try { float f = 5.5; numeric_class<unsigned long> ul(f); char c1 = ul; // function interface converts float to unsigned long AND checks to make sure it is in range Bar(f); // function interface converts char to unsigned long AND checks to make sure it is in range // return float that is in range f = Foo(c1); // if we get here we have a valid f } catch(std::exception const &ex) { std::cerr << "EXCEPTION: " << ex.what() << "\n"; } return 0; }

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STL compatible tables
by Arkadiy Vertleyb 12 Feb '04

12 Feb '04

Hi all, I am re-posting this message in hope that the lack of responce is somehow related to incorrect moment I chose for the original post (just hours after 1.31.0 was released). Please indicate if you have any (potential) interest in this library. Thanks, Arkadiy ============================================= Dear Boosters, A while ago we introduced RTL the Relational Template Library a lightweight facility to create relational tables and perform relational operations on them. The main concept RTL operates with is a relation, which has two types of models: tables and operators. Tables can store, in a type safe manner, fields of any types that satisfy requirements imposed by a typical STL container. Operators store references to their arguments, and produce data on the fly. Both provide iterators that can be used in STL algorithms. Any relation (operator or table) can serve as an argument to yet another operator, thus forming an arbitrary complicated expression tree. A relation has a sort order, which is calculated at compile time based on the sort order of its arguments. Range queries are available, based on this sort order. RTL allows to index any relation, which again can be either a table or a relational operator. In this sense our indexing models the ORDERED BY feature, provided by SQL. Therefore a relational expression can contain any number of indexes, used to re-sort tuples to better suite a particular query or queries. The March issue of C/C++ users journal will contain our article about RTL, where we described the library in more depth. This article reflects the state of the library as of about a year ago. NEW FEATURES ============ This time we are offering a significantly enhanced version of the library. The main addition is the TRANSACTION facility, that allows for synchronized updates to one or more tables. The additional very powerful (in our opinion) benefit is the possibility of incremental index update. When a table is changed, all the indexes that depend on this table get invalidated, and need to be updated. RTL takes care of this by calculating deltas on each index, and applying only necessary changes incrementally. We also modified the library interface to use MPL sequences instead of our proprietary type list implementation, and replaced all our meta-programming code to also make use of MPL. RTL allows the user to choose between available table implementations, as well as define new ones. The current in-stock implementation is based on std::vector, and therefore is most appropriate when the updates dont happen too often. We also experimented with indexed_set library to define a set-based implementation. Since the indexed_set is not a part of boost yet, we do not currently supply this implementation. However we do have it, and if anybody has immediate interest, please let us know well make it available (you will have to download the indexed_set library). We struggled to support VC6 up to the last moment, when some of our tests failed to build with Boost release candidate 2. The problems are with quantitative limitations we are getting ISO, and have to brake down our tests in smaller units. Since Microsoft no longer supports this compiler, we also decided to stop supporting it (we may re-consider if there are significant objections). The library has been tested with VC7.1 and GCC 3.3. Here is the link: http://groups.yahoo.com/group/boost/files/tables.zip As always, we are looking forward to any feedback. Arkadiy vertleyb(a)hotmail.com Dmitriy dmitriy_arapov(a)hotmail.com _________________________________________________________________ Plan your next US getaway to one of the super destinations here. http://special.msn.com/local/hotdestinations.armx

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Boost Test Framework - log and report files
by "Kåsa, Daniel Roy" 12 Feb '04

12 Feb '04

I have just downloaded the latest release of boost so that I could start using the Test Framework. I am part of a fairly large project working on complex software. My project feels as though the boost test framework is beginning to become more mature and we interested in applying it to our test procedures. I have been working on a prototype test environment for my project using the test framework and I have come across some minor problems: 1. I need to have the test log and report written to two separate files in xml format. (It would be nice to have a DTD of both xml formats) I did this by instructing the framework with the command line argument: --output_format=XML. Now that I had both the log and result report in XML format I needed to create two file streams to redirect the output of them to each their own file. This was easy to achieve with the log using the set_log_stream method, but not so trivial with the result report. Calling the singleton of the result report before the test framework has initialized my code first calls a null pointer crashing the test. How should this be done? The documentation states that the interface of the unit_test_result does not need to be used directly, but in my case where I want a file stream instead of the std::err I need to have access to the singleton and preferable in the same place I set up the rest of my test suites. 2. To achieve pt 1 I needed to edit unit_test_framework.hpp (I think). I wanted to add support for my own command line argument which would instruct the framework of the two files I would like to create. So I thought it would be convenient to use the reteive_framework_parameter method to retrieve my custom command argument. Sadly enough I noticed that the method doesn't return the value assigned to my argument unless it is recognized. Is this fair? Daniel R. Kåsa

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