October 2008 - Boost - lists.preview.boost.org

[shared_ptr] Why operator< uses internal_less?
by dariomt＠gmail.com 10 Oct '08

10 Oct '08

I see that operator== and operator!= are implemented comparing the pointer inside the shared_ptr's using get(), but operator< uses _internal_less, that does a different thing. I thought that operator< would also be implemented using get(), so please, can you share the rationale behind the need for _internal_less? TIA

7 6

[1.37] Trivial but Boost wide patch?
by John Maddock 10 Oct '08

10 Oct '08

There's a problem in 1.37 as it stands in that: * If Boost.TR1 is in the include path, and, * A Boost header is included that includes <cmath>. Then the TR1 version of <cmath> gets included. This is relatively harmless on *nix platforms - except for somewhat longer compile times - but for windows compilers that support auto-linking then the headers want to link to the math TR1 libraries even if the user is actually using a header only library like spirit for example. This is the subject of bug report: http://svn.boost.org/trac/boost/ticket/2392. There is a trivial fix, which is to replace #includes of <cmath> with <boost/config/no_tr1/cmath.hpp>: I've just applied this to Trunk (so you know who to blame if this causes any issues!), but should this be applied to the release branch as well? Changeset here: http://svn.boost.org/trac/boost/changeset/49254/trunk Regards, John.

2 1

[graph] compilation broken when mpi enabled
by Juergen Hunold 10 Oct '08

10 Oct '08

Hi ! It seems that change 49178 http://svn.boost.org/trac/boost/changeset/49178 broke compilation of Boost.Graph when mpi is configured. That might be the reason the regression tests are still green. (Would be nice if the Graphiz Loader had some UnitTests, too ;-)) This commit changed libs/graph/build/Jamfile.v2 to contain: > + > +############################################################ > +# Distributed-memory parallel graph library (Parallel BGL) # > +############################################################ > +use-project /boost/mpi : ../../mpi/build ; > +import mpi ; > +if [ mpi.configured ] > +{ It seems that Doug committed some local changes by accident. Please add either the missing files or revert libs/graph/build/Jamfile.v2. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

2 1

[1.37][mpl] Merge gcc 4.4 fix.
by Daniel James 10 Oct '08

10 Oct '08

Hi, It it okay to merge the mpl part of this change to release? http://svn.boost.org/trac/boost/changeset/48960/ It fixes a preprocessor error in gcc 4.4 which stops a lot of libraries from working with that compiler. The python part of the patch isn't required, the error is due to mpl's preprocessed headers not including the boost preprocessor headers and doesn't occur in other libraries that use iteration, as they always include the headers. I've had a look through the test results and everything seems to be working. Daniel

2 1

[accumulators] Dependent and sliding accumulatos_set
by vicente.botet 10 Oct '08

10 Oct '08

Hi, The acuumulator library allows to determine dependency between accumulator, but not between accumulator_sets. I would like to define an accumulator_set c so when we cumulate in two others c1 and c2 accumulator_set we cumulate also in c, some thing like typedef dependable_acumulator_set <double, ...> dependable_acc_type; dependable_acc_type c1, c2; dependable_acc_type c=c1+c2 dependable_acc_type c3; c+=c3; c1(1); c2(1); c3(2); assert(count(c)==3); assert(sum(c)==4); How dependable_acumulator_set can be defined? Here follows the interfaces of such a class and the pseudo code, I've named the class dependable_acumulator_set, sorry but I have not found a shorter and better name (may be observed/listened?) template <typename T, typename F, typename W> class dependable_acumulator_set : public acumulator_set<T,F,W> { public: dependable_acumulator_set(); void add_dependent(dependable_acumulator_set&); void remove_dependent(dependable_acumulator_set&); template<typename A1> void operator ()(A1 const &a1) { for (acc in dependents) { acc(a1); } this->acumulator_set_type::operator()(a1); } dependable_acumulator_set<T,F,W>& operator+=(dependable_acumulator_set<T,F,W>); dependable_acumulator_set<T,F,W>& operator-=(dependable_acumulator_set<T,F,W>); }; template <typename T, typename F, typename W> dependable_acumulator_set<T,F,W> operator+()(dependable_acumulator_set<T,F,W>,dependable_acumulator_set<T,F,W>); In addition I would like to be able to cummulate on a sliding window, e.g. on the last N cummulated values. I have see the tail accumulator, but I dont know how to define a min_tail accumulator with the current framework. I would like a class that behaves like: typedef sliding_acumulator_set <double, ...> sliding_acc_type; sliding_acc_type c(window=2); c(1); c(5); c(2); assert(count(c)==3); assert(sum(c)==7); assert(min(c)==2); We can state the sliding window at compile (template parameter) or run time (constructor parameter). template <std::size Window, typename T, typename F, typename W> class static_sliding_acumulator_set; template <typename T, typename F, typename W> class sliding_acumulator_set; Of course the complexities of the sliding accumulators operations is increased. Of course it will be interesting to have a sliding dependable accumulater set. It would be great to integrate these features on a unique class (accumulator_set?) in a clean way. template <typename T, typename F, typename W, typename DependablePolicy, typename SlicingPolicy> class acumulator_set; Please let me know if this can be done in a better way. Is there any interest on these features? Eric, what do you think? Best, Vicente

1 0

[wave] disabling msvc warnings
by Jürgen Hunold 09 Oct '08

09 Oct '08

Hi ! The current Jamfile for building Wave disables MS "secure" STL and C-Runtime warnings only for msvc-8.0. Please find a patch attached which removes the toolset version and thus eliminates the warnings for 9.0 (and above too). Rationale: Those "features" are not likely to disappear and mvsc version less than 8.0 are slowly dying out. Okay to commit ? And merge to release ? Or use an extra check for 9.0 ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

3 7

1.37 release schedule?
by John Maddock 09 Oct '08

09 Oct '08

Are we on time for the 1.37 release? I notice that the deadline for routine changes passed without any comment (or most of us noticing I suspect). Just checking up on where we are, Cheers, John.

11 20

is_range metafunction
by Neal Becker 09 Oct '08

09 Oct '08

I could use one to enable a range constructor only where appropriate: class X { template<typename range_t> X (range_t const&, enable_if<is_range<range_t> >::type *dummy=0) Question is, what might 'is_range' look like?

7 26

Math Toolkit Distribution Explorer - Windows program now available for download from SourceForge
by Paul A Bristow 09 Oct '08

09 Oct '08

Although the source is included in the Math Toolkit in Boost release, it may be helpful to know that a pre-built package is now available for download from Sourceforge, so I trust it is in order to announce it here. http://sourceforge.net/projects/distexplorer/ Distribution Explorer is a mixed C++ and C# application that allows you to explore the properties of various statistical distributions, and calculate the Cumulative Distribution Function CDF, Probability distribution Function PDF, or quantiles/percentiles. Written using open-source C++ from the http://www.boost.org Boost Math Toolkit library. Some sample screenshots are available which will allow to you to decide if it will cover the statistical distribution you are interested in. There are no pretty pictures :-( but the numbers are rather accurate :-) Download Instructions The Distribution Explorer is distributed as a single Windows Installer package Setupdistex.msi zipped to distexplorer.zip. Download this file and unzip to a temporary location of your choice, for example your desktop, and run setupdistex.msi. This will install a program executable, boost_math.dll and an icon to your Program files/Boost/Distex/ folder (unless you chose another location) and add a shortcut to your Start, Programs menu. If you are updating, you must remove the previous version first using Control Panel. Add/Remove programs. (Note that Microsoft .NET Framework 2.0 and VCredist are requirements for this program. Most recent and updated Windows environments will already have these, but they are quickly, easily and safely installed from the Microsoft site if required.) Enjoy. 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

1 0

[multi_array] Access a view's index_range
by Robert Jones 09 Oct '08

09 Oct '08

How do I access the index_range of an array_view? ie., typedef boost::multi_array<Cell,2 > Grid; Grid grid( boost::extents[9][9]); Grid::array_view<2> view = grid[indices[range(), range()]]; for (Grid::index i = view.?????.start(); i != view.?????.finish(); ++i) {....} where I'm expecting i to take values 0..8 inclusive. Thanks - Rob.

1 0