- Boost - lists.boost.org

multi-array problem
by Neal Becker 25 Jul '06

25 Jul '06

I ran into a problem using multi-array. Not really a "bug", but a bit of unexpected behavior. Most containers have constructors like: template<typename old_t> Container (old_t const&); Allows constructing the new container from any sequence - the new container will have a copy of the contents of the old (usually). If you try this with multi-array you will not get a compilation error, but also will not get anything like what you expected.

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Create a boost/algorithm/math sub-library?
by Daryle Walker 25 Jul '06

25 Jul '06

We have a general algorithms directory, currently with a subdirectory with string routines. I want to add a parallel subdirectory with math routines. The routines I want to add are for the Greatest Common Factor and the Least Common Multiple. Now, I already have a header for that in Boost at $ROOT/boost/math/common_factor_rt.hpp, but the main function and function object class templates in that header encapsulate the real implementation. It's those implementation functions that I want to public place in the algorithm collection. They would be: 1. GCD for unsigned numbers and other non-signed entities, like polynomials, using division & modulus reduction. 2. GCD for signed entities; similar to [1] but there are sign comparisons and possible negations, which types in [1] don't have to support. 3. GCD for binary unsigned integers using bit-level operations; it has the same complexity as [1] and [2], O(digit_count^2), but is generally faster because bit twiddling is faster than division. The wrapping code currently in the math libraries, and elsewhere, would be changed to call these routines. Would this require a full-blown review, a mini-review, or no review? Note that we currently do _not_ implement [3] anywhere in Boost (AFAIK). For the future, I envision algorithm/math to only hold function (templates) that compute specific ways to evaluate a relation of interest. Full blown wrapping functions and function objects, as well as types, would stay within the regular math libraries (and call the algorithms as needed). -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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Incorrect library naming in bbv2
by John Maddock 25 Jul '06

25 Jul '06

The current name mangling scheme in bbv2 still doesn't match bbv1 and the auto-linking code. In particular if I build a library as a dll with msvc it doesn't get a "-mt" part in the library name, even though all builds against the dll runtime *are* multithreaded in msvc. Thanks, John.

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[Boost-bugs] [ boost-Bugs-1528178 ] ublas: bug in mapped_vector_of_mapped_vector
by SourceForge.net 25 Jul '06

25 Jul '06

Bugs item #1528178, was opened at 2006-07-25 05:54 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1528178&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Resolution: None Priority: 9 Submitted By: Matthias Troyer (troyer) Assigned to: Nobody/Anonymous (nobody) Summary: ublas: bug in mapped_vector_of_mapped_vector Initial Comment: There is a serious bug in the mapped_vector_of_mapped_vector spare matrix type. Rows containing only zero elements are not treated correctly in prod(). The following code should give a vector that contains only 1 in the last element. Instead prod() gives a vector containing 1 in each element. In debug mode this bug is found by the checks: Check failed in file boost/boost/numeric/ublas/detail/ vector_assign.hpp at line 371: detail::expression_type_check (v, cv) Aborted The bug appears in Boost 1.33 as well as in the CVS version #include <boost/numeric/ublas/matrix_sparse.hpp> #include <boost/numeric/ublas/vector.hpp> int main() { boost::numeric::ublas::mapped_vector_of_mapped_vector<double> m (64,64); boost::numeric::ublas::vector<double> v(64); boost::numeric::ublas::vector<double> w(64); v[63] = 1.; m(63,63) = 1.; w = boost::numeric::ublas::prod(m,v); } ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1528178&group_… ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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Re: [boost] [system] - std::terminate() called after throw system_error
by Oliver.Kowalke＠qimonda.com 25 Jul '06

25 Jul '06

Hello, please ignore my previous post - I forgott the try-catch block (what a shame). Oliver

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Re: [boost] [system] system-0.2 request for comments
by Beman Dawes 25 Jul '06

25 Jul '06

On 7/22/06, Kim Barrett <kab(a)irobot.com> wrote: > At 12:10 PM -0400 7/22/06, Beman Dawes wrote: > >* Addition of a header boost/identifier.hpp. For years I've used a > >similar class to provide the type safety and freedom from unwanted > >conversions that is missing when a simple int is used for an identifier. > >This is logically separate from the system stuff, but for convenience is > >included in the system package since error_code.hpp uses it. > > This appears to be very similar in intent to the facility provided by > boost/strong_typedef.hpp, though there are significant differences in > detail. The intents of identifier.hpp and strong_typedef differ. A strong typedef retains all operations on the underlying type in the new type. An identifier only provides a very limited set of operations on the new type. That is so an operation like multiplication of an identifier, which is almost certainly an error, is not permitted and will be detected by the complier. It wouldn't surprise me if Boost has identifier.hpp functionality somewhere, but I'm not aware of anything. --Beman

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Re: [boost] [system] system-0.2 request for comments
by Oliver.Kowalke＠qimonda.com 25 Jul '06

25 Jul '06

Hi, > ~/devTools/boost_cvs/libs/system/build$ bjam ...found 225 targets... > ...updating 14 targets... > gcc-C++-action > ../../../bin/boost/libs/system/build/libboost_system.a/gcc/deb > ug/error_code.o > ../src/error_code.cpp: In function > 'std::string<unnamed>::errno_md(const > boost::system::error_code&)': > ../src/error_code.cpp:190: error: invalid conversion from > 'char*' to 'int' > ///that's the while condition here... > > char buf[64]; > char * bp = buf; > std::size_t sz = sizeof(buf); > int result; > while ( (result = strerror_r( ec.value(), bp, sz )) == ERANGE ) > { > if ( sz > sizeof(buf) ) std::free( bp ); > sz *= 2; /* Reentrant version of `strerror'. There are 2 flavors of `strerror_r', GNU which returns the string and may or may not use the supplied temporary buffer and POSIX one which fills the string into the buffer. To use the POSIX version, -D_XOPEN_SOURCE=600 or -D_POSIX_C_SOURCE=200112L without -D_GNU_SOURCE is needed, otherwise the GNU version is preferred. */ Oliver

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Who wants Borland support?
by David Abrahams 25 Jul '06

25 Jul '06

In 1.33.1, Boost.Parameter supported Borland. In 1.34, we are running into compiler bugs that we don't know how to avoid. Somehow the compiler is mis-deducing the return type of operator[] on line 328 of boost/parameter/aux_/arg_list.hpp (see http://engineering.meta-comm.com/boost-regression/CVS-RC_1_34_0/developer/i…) If we can't find a solution to this problem very soon we'll have to mark these tests as expected failures and drop support of Borland for 1.34, and we're stumped. I'm hoping someone who cares about Borland will help us come up with an answer. Thanks, -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Ace??? (was: ANN: POCO - C++ Portable Components)
by Sohail Somani 24 Jul '06

24 Jul '06

> -----Original Message----- > From: boost-bounces(a)lists.boost.org > [mailto:boost-bounces@lists.boost.org] On Behalf Of val salamakha > > Look at Chapter 5 "The ACE Service Configurator Framework" in > "C++ Network Programming" v2 of D. Schmidt . The chapter is > about the subject of your discussion and explains how it works. I have yet to understand why I need to buy a textbook to use ACE. Tthe website is not that good. Not nearly as good as boost.

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Re: [boost] [mpl] Metafunction terminology - revival?
by JOAQUIN LOPEZ MU?Z 24 Jul '06

24 Jul '06

----- Mensaje original ----- De: David Bergman <David.Bergman(a)bergmangupta.com> Fecha: Lunes, Julio 24, 2006 9:11 pm Asunto: Re: [boost] [mpl] Metafunction terminology - revival? > Joaquin wrote: > > [snip] > > > I've reread the referred page, and all I can take it to > > define is: a lambda expression is a metafunction class or a > > placeholder expression. Whether this is what the authors actually > > *meant* is debatable, of course. > > What I think it literally means is that a lambda expression is > either a metafunction class or a placeholder expression, much > like a woman is either nice or mean. This does NOT imply that all > nice people are women ;-) So, I think even the literal reading of > the refered sentence(s) leaves room for non-lambda-expressive > metafunction classes... "A woman is either nice or mean" is not a definition of the term "woman", yet the referred page stands for a definition of "lambda expression", so an "if and only if" implication is assumed. OK, Abrahams and Gurtovoy's book's chapter 3 has been webpublished at artima.com and there you can read the following: ( http://www.artima.com/cppsource/metafunctions2.html ) "We'll refer to metafunction classes like add_pointer_f and placeholder expressions like boost::add_pointer<_1> as lambda expressions." (add_pointer_f is a metafunction class defined a couple of paragraphs before.) Does this convince you? Anyway, we're not discussing Aristotle or Descartes, on the contrary we enjoy the presence of MPL authors amongst us and can always ask them directly. [This does not detract from the fact that your choice of terminology is probably superior, I'm only nitpicking you for the joy of discussion. I hope you're taking it similarly :) ] > [...] > > <pedantic digression> > > Just to play devil's advocate, what gives a lambda expression > > its essence, at least in mathematical lambda calculus, is not > > the presence of place holders, but the ability to apply to > > actual arguments, > > No, that is not true, actually, since that essence of > applicability is best captured by the notion of "function." A > lambda expression is a special type of function (or, rather, > lambda expressions are isomorphic to a set of functions...) I'd say lambda calculus captures aplicability better than the cartesian definition of function as a special subset of a product set AxB, but well, it's hard to argue this objectively. [...] > /David Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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