June 2006 - Boost-users - lists.preview.boost.org

Converting epoch(long) to ptime in Boost.Date_Time
by gdprosch＠micron.com 23 Aug '06

23 Aug '06

I would like to convert epoch(long) time values to boost ptime and vice versa. On the surface this seems relatively easy but some of the functions needed are missing and there is an issue ensuring that the local time is properly applied. Has someone come up with an easy way to do this? I can convert to ptime like this... long epoch_in = 1140411002; // 2006-Feb-19 21:50:02 std::time_t stdtime ( epoch_in ); ptime = from_time_t( stdtime ); To convert from ptime back to epoch(long) there is no conversion provided the other way. I found some code the author supplied a few years ago here: http://lists.boost.org/MailArchives/boost-users/msg07254.php Unfortunately, the result does not correctly apply local time. The following code... std::time_t to_time_t(ptime t) { ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); } ... produces a date with the value: 2006-Feb-20 04:50:02 and not 2006-Feb-19 21:50:02 (I am in US MST). I've played around with applying the local offset but I end up with a lot of lines of code that leave me wondering if there is a better way. It would be nice if it were simple like this (assuming local time adjustment is correctly applied)... long epoch_in = 1140411002; // 2006-Feb-19 21:50:02 ptime pt = from_epoch( epoch_in ); long epoch_out = to_epoch( pt ); Many thanks, > Greg Prosch > Micron Technology, Inc.

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Building boost for 64-bit on AIX
by Patrik Jonsson 17 Aug '06

17 Aug '06

Hi, I'm trying to build boost (1.32.0) on an IBM SP2 under AIX5, using the 64-bit ABI. This is troublesome. I do: bjam "-sTOOLS=gcc" "-sGXX=g++ -maix64 -pthread" --prefix=$HOME --libdir=$HOME/lib64-gcc --includedir=$HOME/include-gcc install But it doesn't work. I get loads of errors like: gcc-Link-action bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so ld: 0711-738 ERROR: Input file bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_month.o: XCOFF32 object files are not allowed in 64-bit mode. collect2: ld returned 8 exit status set -e LIBPATH=bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true:$LIBPATH export LIBPATH "g++" -maix64 -pthread -g -fPIC -shared -o "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_month.o" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_weekday.o" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/date_generators.o" ...failed gcc-Link-action bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so... ...skipped <@boost!lib64-gcc>libboost_date_time-gcc-d-1_32.so for lack of <@boost!libs!date_time!build/libboost_date_time.so/gcc/debug/shared-linkable-true>libboost_date_time-gcc-d-1_32.so... It seems it's using -maix64 ok when trying to build the library, but not when compiling... Can anyone tell me what the proper way of building boost under these conditions are? Thanks, /Patrik Jonsson

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__fastcall warning when compiling boost in managed c++
by ChuMing 13 Jul '06

13 Jul '06

Hi, I am handling some project which mixes managed and unmanaged C++ code. With boost 1.33 I’m hitting problems with the header is_mem_fun_pointer_tester.hpp. There are warnings popping up due to the use of __fastcall calling convertion in boost and its incompatible with compiling some of our code with the /clr flag turned on. Managed C++ is incompatible with the __fastcall calling convention because what it does is it preloads certain registers with the function parameters but for /clr compilation it is compiling to MSIL so this cannot be done and upon encountering any __fastcall the Managed C++ compiler will change it to __stdcall. Does anyone know the implications of disabling these warnings and whether it is safe to do that? I did not get these warnings with the previous versions of boost though. Thanks and regards, Chu-Ming

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Serialization of boost::any
by Sliwa, Przemyslaw (London) 11 Jul '06

11 Jul '06

Does it exist somewhere? Is it planned at all? Thanks for help Kind regards Pshemek Przemyslaw Sliwa Global Foreign Exchange FX Risk Engine Development Merrill Lynch ( +44 (0)20 7995 4182 ) +44 (0)79 6325 2319 * Email: przemyslaw_sliwa(a)ml.com -------------------------------------------------------- If you are not an intended recipient of this e-mail, please notify the sender, delete it and do not read, act upon, print, disclose, copy, retain or redistribute it. Click here for important additional terms relating to this e-mail. http://www.ml.com/email_terms/ --------------------------------------------------------

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[boost.python] use of multi_array in python
by Sebastien Fortier 10 Jul '06

10 Jul '06

I'm having some problems with the use of multi_array's with python. What I'm trying to do is to export some functions that create multi_array's and pass these multi_array's to other functions that will extract other array's from them and display them. Lets say I have this as an example. //ArrayRef2D.h typedef for a 2D multi_array of doubles #ifndef ARRAYREF2D_H_ #define ARRAYREF2D_H_ #include <boost/multi_array.hpp> typedef boost::const_multi_array_ref < double, 2 > const_array_type2D_ref_d_t; typedef boost::multi_array < double, 2 > array_type2D_d_t; #endif /*ARRAYREF2D_H_*/ //Fstd.h 2D multi_array generator #ifndef FSTD_H_ #define FSTD_H_ #include "ArrayRef2D.h" #include <string> using namespace std; class Fstd { public: Fstd(string filename) : filename_(filename){} array_type2D_d_t get2Dfield() { array_type2D_d_t matrix(boost::extents[2][2]); matrix[0][0] = 0; matrix[0][1] = -1; matrix[1][0] = 20; matrix[1][1] = -30; return matrix; } private: string filename_; }; #endif /*FSTD_H_*/ //MatrixAlgorithm2D.h provides methods for displaying and manipulating matrices #ifndef MATRIXALGORITHM2D_H_ #define MATRIXALGORITHM2D_H_ #include "ArrayRef2D.h" #include <cassert> #include <cmath> #include <iostream> using namespace std; class MatrixAlgorithm2D { public: static array_type2D_d_t windChill(const_array_type2D_ref_d_t TT, const_array_type2D_ref_d_t UV) { assert((TT.shape()[0] == UV.shape()[0]) && (TT.shape()[1] == UV.shape()[1])); array_type2D_d_t RE(boost::extents[TT.shape()[0]][TT.shape()[1]]); for (unsigned int x = 0; x < TT.shape()[0]; x++) { for (unsigned int y = 0; y < TT.shape()[1]; y++) { if ((TT[x][y] <= 0.0) && (UV[x][y] >= 5.0)) { RE[x][y] = ( 13.1200 + 0.6215 * (TT[x][y]) + (0.3965 * (TT[x][y]) - 11.3700) * (pow((UV[x][y]),0.16))); } else { RE[x][y] = (TT[x][y]); } } } return RE; } static void display_d(const_array_type2D_ref_d_t a) { for (unsigned int x = 0; x < a.shape()[0]; x++) { for (unsigned int y = 0; y < a.shape()[1]; y++) { cout << a[x][y]; if(y < a.shape()[1] - 1) { cout << ", "; } } cout<<endl; } } }; #endif /*MATRIXALGORITHM2D_H_*/ //matrix.cpp boost.python interface file generated with pyste // Boost Includes ============================================================== #include "boost/python.hpp" #include "boost/cstdint.hpp" // Includes ==================================================================== #include "Fstd.h" #include "MatrixAlgorithm2D.h" // Using ======================================================================= using namespace boost::python; // Module ====================================================================== BOOST_PYTHON_MODULE(matrix) { class_< Fstd >("Fstd", init< const Fstd& >()) .def(init< std::string >()) .def("get2Dfield", &Fstd::get2Dfield) ; class_< MatrixAlgorithm2D >("MatrixAlgorithm2D", init< >()) .def(init< const MatrixAlgorithm2D& >()) .def("windChill", &MatrixAlgorithm2D::windChill) .def("display_d", &MatrixAlgorithm2D::display_d) .staticmethod("windChill") .staticmethod("display_d") ; } I generated my so file with bjam and then Python 2.3.5 (#2, Sep 4 2005, 22:01:42) [GCC 3.3.5 (Debian 1:3.3.5-13)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import matrix >>> dir(matrix) ['Fstd', 'MatrixAlgorithm2D', '__doc__', '__file__', '__name__'] >>> m = matrix.Fstd("HELLO") >>> l = m.get2Dfield() Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: No to_python (by-value) converter found for C++ type: boost::multi_array<double, 2, std::allocator<double> > So you see I can't use my code, what am I doing wrong? I would have liked to declare 2 arrays with get2Dfield() and pass these array to my windChill function to get another 2d matrix which I could then display with my display_d function. -- Sébastien Fortier

2 8

[parameter] Interface questions
by Cromwell Enage 09 Jul '06

09 Jul '06

1. Will BOOST_PARAMETER_IMPL(name) expand to the name of the function that actually "owns" the main body of code? 2. Will there be a way to define a Boost.Parameterized member function outside the class definition? Or should we let the compiler decide whether or not to inline such a function? Cromwell D. Enage __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [Boost-users] [boost] [Announce] Boost Installer for Visual C++ 7.1/8.0
by Trent Nelson 05 Jul '06

05 Jul '06

> Boost Consulting is pleased to announce the availability of a Windows > installer for the current Boost release (1.33.1). See: > > http://www.boost-consulting.com/download.html Any plans to make the .nsi file you're using public? There may be a few of us out there that have experience with Nullsoft and could contribute to the installer in some way, shape or form. Trent.

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[mpl] a few questions about set and map
by Yuval Ronen 05 Jul '06

05 Jul '06

I spent some time reading the mpl docs, and I have a few questions about mpl::set and mpl::map. 1. The docs assert there is a 'front' algorithm for set and map. This sounds weird to me, as the order of the types is them unspecified. But if I'm wrong, and 'front' is in place, then where is 'back'? 2. Where's multiset and multimap? In the boost/mpl directory I see something about multiset, but no real boost/mpl/multiset.hpp header, and there's absolutely nothing about multimap. 3. The docs say that the size of joint_view is the arithmetic sum of the sizes of the sequences of which it's composed. Is that true also in the case of set/map? For an mpl newbie it sounds reasonable that it will removed duplicates and might end up with a size that is smaller than the sum of its components. If it's not, then it sounds quite useless to use it for set/map. Thanks, Yuval

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error using lambdas: conversion from 'x' to non-scalar type 'y'
by klaus triendl 05 Jul '06

05 Jul '06

Hi, I'm rather new to lambdas. I wanted to use them to stream objects into a special stream (not a stl stream). the following code outlines the situation: ---- #include <iostream> #include <list> #include <algorithm> #include <boost/ref.hpp> #include <boost/shared_ptr.hpp> #include <boost/lambda/lambda.hpp> using namespace std; using namespace boost; using boost::lambda::_1; class MyStream { public: MyStream() {} }; class MySubStream: public MyStream { public: MySubStream(MyStream*) {} }; MyStream& operator <<(MyStream& os, const int&) { return os; } int main() { list<shared_ptr<int> > cont; MyStream osTop; MySubStream osSub(&osTop); for_each(cont.begin(), cont.end(), ref(osSub) << *_1); return 0; } ---- g++ outputs error: '/usr/include/boost/lambda/detail/operator_lambda_func_base.hpp:212: error: conversion from 'MyStream' to non-scalar type 'MySubStream' requested'. MS VC 2003.net says: boost\lambda\detail\operator_lambda_func_base.hpp(212) : error C2664: 'MySubStream::MySubStream(MyStream *)' : cannot convert parameter 1 from 'MyStream' to 'MyStream *'. The question is whether my code is correct at all and how I could use lambdas the right way. Thanks! Klaus Triendl

2 4

When to use thread.join()
by Simon Reye 04 Jul '06

04 Jul '06

My apologies if this has been covered. I am new to boost and have been working with the boost thread class. I assume that the join() function waits for the thread to finish execution. But what if the thread has already finished executing? Can I still call join() and have it not wait for infinity? Simon

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