March 2010 - Boost-users - lists.preview.boost.org

[GSoC]
by Andrew Sutton 29 Mar '10

29 Mar '10

Just a reminder, Google Summer of Code student applications can now be submitted here [1]. The deadline for submitting an application is Apr 9. Ideas for some student projects and other information about the program can be found here [2]. Andrew Sutton andrew.n.sutton(a)gmail.com [1] http://socghop.appspot.com/ [2] https://svn.boost.org/trac/boost/wiki/SoC2010

1 0

boost/type_traits/has_new_operator.hpp and NVCC
by Denis Taniguchi 29 Mar '10

29 Mar '10

Hi all, I'm trying to compile boost::numeric::ublas with NVCC and I get the following errors: /usr/local/include/boost/type_traits/has_new_operator.hpp:28: error: `&' cannot appear in a constant-expression /usr/local/include/boost/type_traits/has_new_operator.hpp:28: error: template argument 2 is invalid This is related to #3919 and #3980 in a effort to make NVCC work with boost. Is there a known workaround so that I could tweak boost/config/compiler/nvcc.hpp? I'm using trunk under linux with the following piece of code: // Boost headers #include <boost/numeric/ublas/matrix.hpp> int main() { typedef boost::numeric::ublas::matrix<float> host_matrix_type; host_matrix_type host_mat; return 0; } Regards, Denis

2 3

Re: [Boost-users] Boost serialisation: base ptr regression in 1.42
by Avi Bahra 29 Mar '10

29 Mar '10

The warning messages have gone when I used a const object. Thanks. However the "*unregistered class* " crash still remains if the if base/derived classes are placed in a static lib. (for 1.42 only). Robert Ramey wrote: >EXPORT has been made a little bit more elabort to >separate issues of code instantiation for class registration. These >changes were necessary to make EXPORT work properly with >DLLS. Look at the 1.42 documentation for an explanation. Not sure I understand this. In the 1.42 documentation under "Export Key" it says: "For programs which consist of only one module - that is programs which do not use DLLS, one can specify BOOST_CLASS_EXPORT(my_class) or BOOST_CLASS_EXPORT_GUID(my_class, "my_class_external_identifier") in either he* declaration header or definition*. These macros expand to invocation of the of both of the macros described above. *(GUID stands for Globally Unique IDentfier.)" * So I am not using DLL's, and have used BOOST_CLASS_EXPORT(Derived); in the implementation class. So the work around for unix's looks like: 1/ Place the BOOST_CLASS_EXPORT in the implementation and use explicit type registration 2/ Place the BOOST_CLASS_EXPORT in the header *_only_* In either case this is significant change, and should merit mention in the 1.42 release notes, and a change to the documentation Best regards, Ta, Avi

2 1

newbie question - C++
by Figa Pelosa 29 Mar '10

29 Mar '10

hello, I'm using boost for the very first time and I'm having big problems in understanding how to proceed. I'm working in C++, and my aim would be creating a graph where each node is a 2D point and each edge is the distance between two points. I'd like to be able to say "vertex 0 and vertex 1 are 5mm apart". How to do that? This is what I got so far: typedef boost::adjacency_matrix<boost::undirectedS> Graph; class myClass { private: int numberOfNodes; Graph *g; char* name; public: myClass(int); addVertex(float,float,int); void addEdge(int[2],int); }; myClass::myClass(int number)fNodes){ g = new Graph(number_of_nodes); } myClass::addVertex(float x,float y) { add_edge(x,y,*g); } Now this seems to work, but how to incorporate coordinates? Thanks a lot for your help! Ale

1 0

A question on the preciseness of the double used in MTL. Can anyone with kindness help me?
by fmingu 29 Mar '10

29 Mar '10

I am using MTL(Matrix Template Library) for Matrix computing in Dev-C++ 4.9.8.0 and updated the gcc version from 3.2 to 4.4.1 by installing tdm-mingw-1.908.0-4.4.1-2 and the boost version is 1.37.0. The system is Windows xp The sample code is : #include <boost/numeric/mtl/mtl.hpp> #include "boost/random/normal_distribution.hpp" #include <boost/random.hpp> #include <boost/random/uniform_real.hpp> int main(int argc, char* argv[]) { using namespace mtl; using namespace mtl::matrix; const unsigned n= 5; dense2D<double> A(n, n), B(n, n); morton_dense<double, doppled_64_row_mask> C(n, n), D(n, n); dense2D<double> F(n, n), E(n, n); hessian_setup(A, 3.0); hessian_setup(B, 1.0); hessian_setup(C, 2.0); hessian_setup(D, 11.0); B(1,1)=9.9999; .......................... std::cout << "The matrices are: B=\n" << B <<"\n"; std::cout << "The result is " <<1.0/3.0 <<"\n"; ……………………. But the result is shown that B(1,1) is 10, and 1.0/3.0 is 0.33. How can I get the highest precision of the type double and dense2D<double> for scientific computation? The same question occurred in random number generation in boost random library. Can anyone with kindness help me?

2 1

compiler(iropt) error: get_leaf_hash_index: unknown constant type
by Iskandar Prins 29 Mar '10

29 Mar '10

Hi, When compiling certain boost features I get this error with the Sun Compiler (SunOS 5.10, x64) compiler(iropt) error: get_leaf_hash_index: unknown constant type I'm including the following: #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/mean.hpp> #include <boost/accumulators/statistics/kurtosis.hpp> #include <boost/accumulators/statistics/moment.hpp> #include <boost/accumulators/statistics/variance.hpp> #include <boost/accumulators/statistics/skewness.hpp> I'm using boost 1.42.0, any idea why this is? Regards, Iskandar

1 0

[mutex] Error in static method
by Daniele Barzotti 29 Mar '10

29 Mar '10

Hi, I have a class which defines a static callback: -------------------------------------------------------------- class CDeviceManager { private: struct TCallbackUserData { CDeviceManager* ptrThis; INT CurrentApi; }; // Since the callback is static, I need this struct to pass data TCallbackUserData CBUserData_; boost::mutex Mutex_; }; INT CDeviceManager::audio_callback(void *outputBuffer, void *inputBuffer, UINT nBufferFrames, double streamTime, RtAudioStreamStatus status, void *userData ) { CDeviceManager* This = 0; TCallbackUserData* UserData = (TCallbackUserData*)userData; This = UserData->ptrThis; // Used if the audio device is opened with simultaneous API boost::lock_guard<boost::mutex> lock(This->Mutex_); } -------------------------------------------------------------- But on compiling I get: 1>d:\lib\boost_1_42_0\boost\thread\win32\mutex.hpp(38) : error C2248: 'boost::noncopyable_::noncopyable::operator =' : cannot access private member declared in class 'boost::noncopyable_::noncopyable' 1> d:\lib\boost_1_42_0\boost\noncopyable.hpp(28) : see declaration of 'boost::noncopyable_::noncopyable::operator =' 1> d:\lib\boost_1_42_0\boost\noncopyable.hpp(22) : see declaration of 'boost::noncopyable_::noncopyable' 1> This diagnostic occurred in the compiler generated function 'boost::mutex &boost::mutex::operator =(const boost::mutex &)' I know that the mutex is noncopyable, but I use this many times. It depends by the 'static' method? Regards, Daniele.

1 0

[mpl] Constant time mpl::contains<mpl::set>
by strasser＠uni-bremen.de 29 Mar '10

29 Mar '10

Hi, I'd like to be able to query if a MPL Sequence contains a certain type, aka mpl::contains. But mpl::contains is documented to always have linear complexity, even for mpl::set's. How can you differentiate between types of MPL Sequences, so you can use mpl::at for sets and mpl::contains for vectors? MPL itself seems to do this by template specialization, e.g. for mpl::at, which is overloaded. But template specialization relies on MPL implementation details, is there a way to detect any type that models an associative sequence? I can't find something like mpl::is_set nor a tag to dispatch with in the AssociativeSequence concept. Thank you, Stefan

2 1

Compiling with Sun C++ 5.8 Patch 121018-11 2007/05/02
by John Ky 29 Mar '10

29 Mar '10

Hi all, Has anyone had any success with compiling boost 1.42.0 with Sun C++ 5.8 Patch 121018-11 2007/05/02? Cheers, -John

1 0

[serialization] Are there libraries to deserialize XML for any scripting languages?
by Martin Muggli 29 Mar '10

29 Mar '10

Hi, I'd like to be able to work with the data serialized using the xml_oarchive serializer in a scripting language for rapid development of a debugging/diagnostic tool. It seems conceivable a library could construct a native representation of a C++ object model. I would think it could do this using just the serialized XML since most scripting languages allow dynamic creation/modification of classes and objects. I've searched the web for such a thing, but didn't stumble across anything. Can anyone point me toward any work that's been done in this area? A possible alternative that comes to mind is to use py++ to generate Python/boost.Python bindings to the original C++ classes and just use the boost::serilization XML deserializer, but I'm concerned getting all that working will offset the time savings of a scripting language. Thanks in advance, Martin This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.

2 1