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GSoC project "Visualization of STLContainers as SVG" - possible features?
by Paul A Bristow 25 May '07

25 May '07

I've been collecting a shopping list of possibly desirable features for Jake Voytko's GSoC STL containers as SVG plots. Project and class names? Boost.Plot? - as Boost.Graph is 'spoken for' - and does that mean that to avoid confusion we should always use the work plot rather than graph? Like svg_plot my_plot("my_plot1.svg"); rather than svg_graph my_graph("test.svg"); // Construct class Best to get the name right as early as possible? Features of plots I have thought that are (or might be) wanted are: General ======= * overall (called chart area in Excel - is this the right name?) background box colour, if any. * background border? colour, if any Axes ==== * axes area background and/or border? (called plot area in Excel) * title, font, size and colour * axis lines, thickness, colour? * axis labels (and perhaps separate units) default x axis (y axis, z axis)? * axis markers (or not), major (and minor?) width, length and colour. default of these, marks inside or outside * (separate for x, (y and z), logarithmic, and anti) axis?/axes * axis marker labels - as vector of pairs of values and short strings of values? max, min, Auto option, axis * must go through origin? * should axes be scaled, for example, if all values are in range 1e-6 to 9e-6, should be axes be 1. to 10. with a scale factor of 1e-6? Data ==== * data marker symbol like * x . | |_| etc, size, boldness and color (and outline?). Lines or Blocks can be used to show 1D as histograms if they can optionally be used to stack on top of each other. * data value labels? - showing the x (y & z) value of each data point: font, size, colour, position? format? * should data values be show with the same scale factor as axes, or include any exponent 1.23e6? * multiple data series, * series legend, position (top, bottom , left right exact) , font, colour, border? * gridlines?? Not a priority,but some people will probably want them, sometimes. * lines (colour, thinkness) and/or curves joining data points. * lines representing a fitted line or curve - lower prority as users can always do this themselves. * Will need greek for all sorts of text (labels, title legends), so use Unicode strings? Need sub and superscript too, and other symbols like sqrt? Maybe worry about this later? data sources ============ x data points in 'container' (C array, Boost array, std::vector, std::list, std::deque, circular_buffer) (I'm using container to include C arrays that are not strictly STL containers). * Default is to plot all in the container, but also: count of values, starting with 1st, index of 1st and last values. iterator to 1st and last. * Similarly for x & y data (perhaps even x & y & z data). * y values at equally spaced x with start and finish indexes and iterators, or count of values? Default for array, vector...? * array x values, array y values, container x & y pairs, (container x, y, z as tuples) * container of 'points' as a struct double, double? * Function like y = mx + c, y = sin(x) ... as source (but need to specify the limits of x (and/or y??)). (This will also be useful to show fitted lines or curves on top of the data points). * need to provide svg class member functions with defaults for all, as well as control of *all* details. * getter functions like my_graph.point_color() returning red? Views on priorities, and things I have missed? Paul --- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539561830 & SMS, Mobile +44 7714 330204 & SMS pbristow(a)hetp.u-net.com

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[filesystem] recursive_directory_iterator::pop() question
by Alexei Alexandrov 25 May '07

25 May '07

Hi, recursive iterator in the Boost Filesystem library has a function pop() which allows to break iteration over current level directory. But at the same time, recursive iterator doesn't seem to give any guarantees about the order of iteration regarding files and directories. But without such guarantees pop() seems to be pretty useless. What I'm missing? Is there any valid use case for recursive_directory_iterator::pop() at all?

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[bimap][multi_index][range] sub_range vs std::pair<iter, iter>
by Matias Capeletto 25 May '07

25 May '07

Hi, Boost.MultiIndex and Boost.Bimap implements a function named range. It is designed to integrate well with the new Boost.Range framework. The actual signature is: template< class LowerBound, class UpperBound > std::pair<iterator,iterator> range(LowerBound lower, UpperBound upper); template< class LowerBound, class UpperBound > std::pair<const_iterator, const_iterator> range(LowerBound lower, UpperBound upper) const; In bimap docs it is stated that the way to use it is: typedef bimap<string,int> bm_type; bm_type bm; //... std::pair<bm_type::left_iterator, bm_type::left_iterator>r = bm.left.range(...,...); I want to know if this is the best approach. Boost.Range defines two range classes (iterator_range and sub_range) http://www.boost.org/libs/range/doc/utility_class.html It is said that they are better abstraction for ranges that std::pair<iter,iter> 1) Do you think that the range functions should return a sub_range<map_type> instead of a std::pair<iter,iter>? The signature will be: template< class LowerBound, class UpperBound > sub_range<map_type> range(LowerBound lower, UpperBound upper); template< class LowerBound, class UpperBound > const sub_range<map_type> range(LowerBound lower, UpperBound upper) const; 2) In any case do you think that including typedef for the returned range type will make code more readable? The idea is to define: typedef -range_type- sub_range; // the name can be different typedef -const_range_type- const_sub_range; So the user code will look like this: typedef bimap<string,int> bm_type; bm_type bm; //... bm_type::left_sub_range r = bm.left.range(...,...); Best regards Matias

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Review Schedule - Spring 2007
by Tom Brinkman 25 May '07

25 May '07

We need review manager volunteers for most of the libraries in the review queue. If your interested, let us know by replying to this thread. Preferably, you would have a background in the problem domain, a regular contributer to the boost mailing list, but no association with the library. Some of the libraries have been waiting patiently for a volunteer for some time now. 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: 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: Martin Vuille 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: 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: Switch Author: Steven Watanabe Location: Boost Sandbox Vault http://tinyurl.com/yvssgx Review Manager: Needed Date: Needed Introduction: The built in C/C++ switch statement is very efficient. Unfortunately, unlike a chained if/else construct there is no easy way to use it when the number of cases depends on a template parameter. <TODO: more description needed>

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[bimap] Added to CVS (and question about images in CVS)
by Matias Capeletto 25 May '07

25 May '07

Hello, Boost.Bimap sources has been added to Boost CVS, and I include it in /status/Jamfile.v2. The html files of the docs are about 1.3MB. The images and diagrams sum up other 1.1MB. Can I add this files too in the CVS? Regards Matias Capeletto

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[optional] Making optional more debugger friendly
by Jeffrey Faust 25 May '07

25 May '07

My only complaint about boost::optional is that it is very difficult to see values in the debugger. I brought this up in a discussion at BoostCon, and Jeff Garland suggested I submit a patch. Well, I have a patch. The change introduces a new private T* m_value and protected method update_debug() which sets this variable. The variable is only visible when building debug, and the method is empty in non-debug. From there, I simply call update_debug() in each public method that changes the storage. The final result is that debuggers can see the variable data by looking at opt.m_value. When not set, the value is null. Any thoughts? Jeff Faust

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[iostreams] Iostreams status?
by Aaron W. LaFramboise 24 May '07

24 May '07

What is the status of Boost.Iostreams? I've noticed: 1) The original author does not seem to be available. 2) Significant portions of the documentation remain incomplete. 3) Asynchronous streams and other issues brought up during review appear to be incomplete. Is anyone still working on this library? Is it being proposed for standardization? Are there any other planned Boost libraries that do a similar thing to this one?

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[extensions] some implementation questions
by Felipe Magno de Almeida 24 May '07

24 May '07

1. What is BOOST_EXTENSIONS_IMPL_NAMESPACE_BEGIN used for? It doesnt seem to add anything useful. Just complicates the implementation. 2. Why is functor defined? Why not use boost::bind and boost::function ? 3. Why does shared_library have two-phase construction? It seems to be common knowledge that two-phase construction is bad. IMO, a default-constructor and a constructor that throws would be better. And member functions for both options too. Now, IMO, factories are unnecessarily complicating the library. Couldn't a different approach be pursued? Like serialization does for type registration. Best regards, -- Felipe Magno de Almeida

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[fusion] Problem in cvs head version of tuples?
by John Maddock 24 May '07

24 May '07

I'm getting errors from fusion in cvs HEAD that I don't see if I use the 1.34 release, only with gcc-3.4 though, not with msvc: In file included from c:/data/boost/develop/boost/boost/fusion/sequence/adapted/struct.hpp:11, from c:/data/boost/develop/boost/boost/fusion/sequence/adapted/std_pair.hpp:12, from c:/data/boost/develop/boost/boost/tr1/tuple.hpp:51, from ../../../boost/math/tools/roots.hpp:13, from ../../../boost/math/special_functions/detail/igamma_inverse.hpp:11, from ../../../boost/math/special_functions/gamma.hpp:1785, from ../../../boost/math/special_functions/erf.hpp:11, from ../../../boost/math/distributions/normal.hpp:16, from test_dist_overloads.cpp:24: c:/data/boost/develop/boost/boost/fusion/sequence/adapted/struct/extension.hpp: In static member function `static typename boost::add_const<typename boost::fusion::extension::struct_assoc_member<Struct, Key>::type>::type& boost::fusion::extension::struct_assoc_member<const Struct, Key>::call(const Struct&)': c:/data/boost/develop/boost/boost/fusion/sequence/adapted/struct/extension.hpp:59: error: type/value mismatch at argument 2 in template parameter list for `template<class Struct, int N> struct boost::fusion::extension::struct_member' c:/data/boost/develop/boost/boost/fusion/sequence/adapted/struct/extension.hpp:59: error: expected a constant of type `int', got `Key' c:/data/boost/develop/boost/boost/fusion/sequence/adapted/struct/extension.hpp:59: error: `call' is not a member of `<declaration error>' Anyone any ideas? Thanks, John.

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[variant]bug: max used instead of lcm
by Larry Evans 24 May '07

24 May '07

The make_storage template at line 215 of: http://boost.cvs.sourceforge.net/boost/boost/boost/variant/variant.hpp?revi… uses max over the alignment_of's for the types in the variant (See line2 233-235) to calculate the variant's alignment. However, to handle the extended alignments described on page 3 of: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2165.pdf the boost::math::static_lcm template should be used instead of max.

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