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type traites - is_virtual_base
by Robert Ramey 29 Mar '09

29 Mar '09

I've noticed that this is returning true when it should be returning false in the tests on 64 bit compilers. Is it possible that 64 bit structure alignment might be breaking the implementation? tests for SUN compilers also manifest this symptom. Maybe the has a similar cause. Robert Ramey

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[gsoc] interest check for BigDecimal class
by kannan venkat 29 Mar '09

29 Mar '09

Hi, I am a student applying for GSoC 2009. I was always interested in a BigInteger class for c++ like the one provided by JAVA.i learnt that it was implemented in a previous year's GSoC. But i could not find it in the boost package i downloaded(i beg your pardon if i am wrong). Please let me know if there is scope to work on that. One more feature missing in boost is a BigDecimal class.Would it be good idea to implement the BigDecimal class with all their functionalities -overloading all arithmetic,assignement & comparison operators , functions for other basic operations. bye kannan

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[gsoc]built-in support for dictionary words
by kannan venkat 29 Mar '09

29 Mar '09

Hi ,I am a student applying for GSoC 2009. I had an idea of providing inbuilt support for English words found on the dictionary. As far as i have searched i found that there isn't support for dictionary words in boost (please correct me if i am wrong & if i am trying to reinvent the wheel). In many situations i had wanted to have a list af all meaningful english words(inclusive of places & common names of people) , specially in cryptographic applications which include deciphering ciphers & other applications related to words(like finding meaningful words in a random grid of characters) . And I could not find any in-built support for this requirement.I had to write my own algorithm to work on an external list. Thus i think it might be useful. I plan to provide *support for list of all meaningful words . *efficient methods to search if a string is a valid english word. *advanced searched options for checking if a given string is a substring is of any valid english word in an efficient manner. *methods to check if any anagram of a given string is a valid english word. could you tell me if this will be a useful contribution & give suggestions if there can be any other useful feature related to this.. bye kannan

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Error In undirected subgraph with no parallel edges
by Sandeep Gupta 28 Mar '09

28 Mar '09

Hi, I am using following declaration to define subgraphs over undirected graph such that parallel edges are disallowed: typedef boost::adjacency_list<vecS, setS, undirectedS, property<vertex_index_t,int>, property<edge_index_t,int> > ImplGraph_t; typedef boost::subgraph<ImplGraph_t> embeddedGraph_t; that is use setS for EdgeList instead of listS. However when I call the function local_to_global over the subgraph i end up following errors: /home/sandeep/Computing/boost_1_38_0/boost/graph/subgraph.hpp:147: error: passing ‘const std::vector<void*, std::allocator<void*> >’ as ‘this’ argument of ‘typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::reference std::vector<_Tp, _Alloc>::operator[](size_t) [with _Tp = void*, _Alloc = std::allocator<void*>]’ discards qualifiers /home/sandeep/Computing/boost_1_38_0/boost/graph/subgraph.hpp:147: error: invalid conversion from ‘void*’ to ‘unsigned int’ /home/sandeep/Computing/boost_1_38_0/boost/graph/subgraph.hpp:147: error: initializing argument 1 of ‘typename std::_Vector_base<_Tp, _Alloc>::_Tp_alloc_type::reference std::vector<_Tp, _Alloc>::operator[](size_t) [with _Tp = void*, _Alloc = std::allocator<void*>]’ Please find the full code that creates the above scenario. Appreciate any help. -Thanks sandeep ///////////////-----------------------Undirected_Subgraph.cpp----------------------------- #include <boost/graph/subgraph.hpp> #include <boost/graph/adjacency_list.hpp> using namespace boost; typedef boost::adjacency_list<vecS, hash, undirectedS, property<vertex_index_t,int>, property<edge_index_t,int> > ImplGraph_t; typedef boost::subgraph<ImplGraph_t> embeddedGraph_t; int main() { embeddedGraph_t G; typedef graph_traits<embeddedGraph_t>::vertex_descriptor vertex_t; vertex_t v; embeddedGraph_t& G1 = G.create_subgraph(); G.local_to_global(v); return 0; }

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[filesystem] detecting hidden files?
by Kenny Riddile 28 Mar '09

28 Mar '09

Does the filesystem library allow you detect whether a path refers to a hidden file or not?

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Re: [boost] [gsoc]built-in support for dictionary words
by kannan venkat 28 Mar '09

28 Mar '09

i got a lot of valuable comments & suggestions . Thanks a lot!! yes bloom filters is the best option for checking if the word is present & for substrings suffix trees should do the trick as Phil Endecott suggested. Inbuilt SpellCheck was a great idea which has practical necessity.I shall try to implement if it can be done within the given period. I shall soon post another idea i had been workin on.

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Can a Boost library use a component like GMP and mfpr that have a LGPL license ?
by Paul A. Bristow 28 Mar '09

28 Mar '09

I am raising this issue for discussion because it seems to me that it is important to resolve this issue before development of the GTL library by Lucanus Simonson and others. I suspect this is not the only time this will crop up, especially with the two very well developed and refined 'big' multiprecision number libraries, GMP (http://gmplib.org) and mfpr (www.mfpr.org) Boost lacks any equivalent libraries (apart from some un reviewed, but probably functional, big integer offerings). GMP and mfpr have already been used within John Maddock's Boost.Math library, but only to calculate extremely accurate reference values, so *users* do not have to use GMP and mfpr. Fernando Cacciola wrote "While in the case of GTL, it is technically up to the user to pick up "their own" multiprecision number types, they actually can't do that without an external non-boost library since such number types do not exists in the SCL." I agree that it would be unfortunate to re-invent the wheel to produce our own (probably inferior) version of these components. So what do we do? Might we enter into discussion with GMP and mfpr developers to get explicit permission to package their library within Boost? IANAL but I feel this issue should be resolved and a decision recorded. Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com

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[Review Request] Msm
by Christophe Henry 27 Mar '09

27 Mar '09

Hi, Msm v1.20 has now been stable for some time and managed to survive a fair number of tests, so I would like to request a formal review. The review-ready version can be found: - in the Vault: http://www.boostpro.com/vault/index.php?direction=0&order=&directory=Msm& - or better (in case of bugfixes), in the sandbox: https://svn.boost.org/svn/boost/sandbox/msm/ . You will find there the Review version under /tags/version-1.20, the most current version at the same level under /boost (or /libs for the doc). Thanks, Christophe

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[Boost.Config] Using <cstddef> instead of <utility> for std lib detection
by David Deakins 27 Mar '09

27 Mar '09

I am in the process of migrating our VeecoFTC regression tests from VC8 and STLport 5.1 to VC9 and STLport 5.2. While working on this, I have experimented with turning on STLport's _STLP_USE_BOOST_SUPPORT macro. When this macro is defined, STLport will pull in the Boost.TypeTraits header files instead of its own type traits implementations. It also suppliments a few of the standard headers (memory and functional) with Boost-based TR1 functionality much like Boost.TR1 does. However, similar to some of what Boost.TR1 had to deal with, some caution is required to avoid circular dependencies in the headers. One area where this tends to come up is in detecting the standard library in use in Boost.Config. Currently config/select_stdlib_config.hpp and config/stdlib/stlport.hpp include <utility> to determine what std library is provided. However, <utility> can tend to pull in some code that wants type traits and thus may circularly pull in Boost. One convenient way to resolve this would be to use the much simpler <cstddef> header instead of <utlity> to determine the std lib. Is this a reasonable change to make or is there something special about using <utility> in the select_stdlib_config code? -Dave

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[gsoc] Status
by troy d. straszheim 27 Mar '09

27 Mar '09

We have 9 proposals. Four of these are for the devector idea: students who have filed these overlapping proposals are encouraged to take the initiative, come up with some ideas and discuss them on the list. We have enough mentors, but it isn't clear that each proposal will match up well with an individual mentor. More mentors welcome to apply. Currently we have no way to make the current set of proposals visible to the general community. I've filed a bug with google and have reason to hope this will get resolved soon. Until then only accepted mentors can see the full list. :/ Students who are working on a proposal who haven't submitted it yet are encouraged to get a draft together, put it up on a webpage or wiki someplace, solicit comments, and refine. This can only help your chances. -t

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