April 2003 - Boost-users - lists.preview.boost.org

Re: [Boost-Users] Re: "Correct" way to return empty shared_ptr?
by dick.bridges＠tais.com 24 Apr '03

24 Apr '03

I don't understand C++ well enough to grok a compiler's interpretation of the code, but I seems like I'm creating an extra copy for the return. Oh well, if the snippet seems ok, far be it from me to throw asparagus on it. ;) Thanks for the help. "Edward Diener" … [View More] <eddielee@tropic To: boost-users(a)yahoogroups.com soft.com> cc: Sent by: news Subject: [Boost-Users] Re: "Correct" way to return empty shared_ptr? <news(a)main.gmane .org> 04/23/2003 05:47 PM Please respond to Boost-Users dick.bridges(a)tais.com wrote: > What is the 'correct' way to return a NULL/empty shared_ptr? For > example, this works > > <snippet> > shared_ptr<int> maybe_get_a_pointer() > { > shared_ptr<int> p; > return(p); > } > </snippet> > > but seems 'klunky'. I've clearly missed something in the > docs/examples somewhere. Can someone point me in the right direction? What is klunky about it ? It seems pretty normal to me. Another other possibility is to passed a reference to a shared_ptr<> and have your function above fill it in with an actual pointer to int and return a bool true if it succeeded or false if it did not. Another possibility is to use boost::optional<>. Another one to pass back a bool,shared_ptr<> std::pair or boost::tuple. But I prefer the method you used originally. Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ [View Less]

1 0

uBlas Lapack binds from Sandbox - VC6 workaround
by geert_ceuppens 24 Apr '03

24 Apr '03

As an introduction; my goal is to link together the uBlas matrix/vector classes with the Intel MKL library (I looked at ATLAS, but the Lapack coverage was insufficient). I have tried the bindings code in the Boost Sandbox (on which Toon and Kresimir are working), but VC6 falls over. I managed to work around the partial template specialisation problem (see my previous postings), thanks to Kresimir's and Toon's feedback. There is however one remaining question I need some help with. … [View More]First the question; after that I post all the code which I've hacked together to assist other interested users using VC6. Due to my ignorance, I am obliged to pass the orientation as a template parameter to the matrix_traits class. What I would like to do is to obtain this information from the matrix class directly. The issue is that matrix_type::functor_type does not exist for all matrix classes. For example, hermitian, triangular and symmetrix matrix use matrix_type::functor2_type to store the orientation of the matrix. With a good compiler (i.e. *NOT* VC6), one could specialise matrix_traits for these matrix classes (at least that is what I think - but this isn't done yet in the ublas_matrix.hpp file in the Sandbox), here however I'm stuck. As a hack, I allow the orientation to be passed as a template parameter. Is there a better way to do this (the matrix class M knows the orientation already)? // M is type of matrix, RC is the row/column orientation template <typename M, // type of matrix typename RC = boost::numeric::ublas::row_major> struct matrix_traits { public: typedef RC row_column_major; typedef M matrix_type; ... static int stride1 (matrix_type& m) { //return matrix_type::functor_type::one1 (m.size1(), m.size2 ()); return row_column_major::one1 (m.size1(), m.size2()); } ... }; Here is the code I wrote: ---------------------//---------------------- traits.h: // (-*- C++ -*- header) /* * * Copyright (c) Kresimir Fresl and Toon Knapen 2002 * * Permission to copy, modify, use and distribute this software * for any non-commercial or commercial purpose is granted provided * that this license appear on all copies of the software source code. * * Authors assume no responsibility whatsoever for its use and makes * no guarantees about its quality, correctness or reliability. * * First author acknowledges the support of the Faculty of Civil * Engineering, University of Zagreb, Croatia. * * --> Modified/simplified for VC6 */ #ifndef BOOST_NUMERIC_BINDINGS_TRAITS_TRAITS_HPP #define BOOST_NUMERIC_BINDINGS_TRAITS_TRAITS_HPP #include <cstddef> //namespace boost { namespace numeric { namespace bindings { namespace traits { // vector_traits<> base: // .. implementation -- do not use it directly template <typename V, typename T = typename V::value_type> struct default_vector_traits { typedef T value_type; typedef T* pointer; // assumption: iterator==pointer // .. e.g. ublas::(un)bounded_array static pointer storage (V& v) { return v.begin(); } static const T* storage (const V& v) { return v.begin(); } static int size (V& v) { return v.size(); } static int size (const V& v) { return v.size(); } static int stride (V& v) { return 1; } static int stride (const V& v) { return 1; } }; // vector_traits<> generic version: template <typename V> struct vector_traits : default_vector_traits<V> {}; // matrix structure tags: struct general_t {}; struct symmetric_t {}; struct symmetric_packed_t {}; struct hermitian_t {}; struct hermitian_packed_t {}; // triangular, banded etc. struct unknown_structure_t {}; /* // matrix_traits<> generic version: template <typename M> struct matrix_traits { // typedefs: // matrix_structure // value_type // pointer // ordering_type // static functions: // pointer storage() // int storage_size() // int size1() // int size2() // int leading_dimension() // not all matrix types // symmetric/hermitian typedefs: // uplo_type }; */ // storage ordering tags: struct row_major_t {}; struct column_major_t {}; // upper/lower tags: struct upper_t {}; struct lower_t {}; // free accessor functions: template <typename VectorT> inline typename vector_traits<VectorT>::pointer vector_storage (VectorT& v) { return vector_traits<VectorT>::storage (v); } template <typename VectorT> inline int vector_size (VectorT& v) { return vector_traits<VectorT>::size (v); } template <typename VectorT> inline int vector_stride (VectorT& v) { return vector_traits<VectorT>::stride (v); } // All the matrix_traits<MatrixT> code has been removed here ... }}}} #endif // BOOST_NUMERIC_BINDINGS_TRAITS_TRAITS_HPP ---------------------//---------------------- ublas_matrix.h: // (-*- C++ -*- header) /* * * Copyright (c) Kresimir Fresl and Toon Knapen 2002 * * Permission to copy, modify, use and distribute this software * for any non-commercial or commercial purpose is granted provided * that this license appear on all copies of the software source code. * * Authors assume no responsibility whatsoever for its use and makes * no guarantees about its quality, correctness or reliability. * * First author acknowledges the support of the Faculty of Civil * Engineering, University of Zagreb, Croatia. * * --> Modified/simplified for VC6 */ #ifndef BOOST_NUMERIC_BINDINGS_TRAITS_UBLAS_MATRIX_H #define BOOST_NUMERIC_BINDINGS_TRAITS_UBLAS_MATRIX_H #include <boost/numeric/ublas/matrix.hpp> #include "traits.h" namespace boost { namespace numeric { namespace bindings { namespace traits { // Need to find a way to extract the orientation class (row / column) template <typename M, // type of matrix typename RC = boost::numeric::ublas::row_major> // row or column major struct matrix_traits { public: typedef RC row_column_major; typedef general_t matrix_structure; typedef M::value_type value_type; typedef M::value_type *pointer; typedef M matrix_type; static pointer storage (matrix_type& m) { typedef typename matrix_type::array_type array_type; return vector_traits<array_type>::storage (m.data()); } static const value_type *storage (const matrix_type& m) { typedef typename matrix_type::array_type array_type; return vector_traits<array_type>::storage(m.data()); } static int size1 (matrix_type& m) { return m.size1(); } static int size1 (const matrix_type& m) { return m.size1(); } static int size2 (matrix_type& m) { return m.size2(); } static int size2 (const matrix_type& m) { return m.size2(); } static int storage_size (matrix_type& m) { return size1 (m) * size2 (m); } static int storage_size (const matrix_type& m) { return size1 (m) * size2 (m); } // stride1 == distance (m (i, j), m (i+1, j)) static int stride1 (matrix_type& m) { //return matrix_type::functor_type::one1 (m.size1(), m.size2 ()); return row_column_major::one1 (m.size1(), m.size2()); } static int stride1 (const matrix_type& m) { //return matrix_type::functor_type::one1 (m.size1(), m.size2 ()); return row_column_major::one1 (m.size1(), m.size2()); } // stride2 == distance (m (i, j), m (i, j+1)) static int stride2 (matrix_type& m) { //return matrix_type::functor_type::one2 (m.size1(), m.size2 ()); return row_column_major::one2 (m.size1(), m.size2()); } static int stride2 (const matrix_type& m) { //return matrix_type::functor_type::one2 (m.size1(), m.size2 ()); return row_column_major::one2 (m.size1(), m.size2()); } static int leading_dimension (matrix_type& m) { //return matrix_type::functor_type::size2 (m.size1(), m.size2 ()); return row_column_major::size2 (m.size1(), m.size2()); } static int leading_dimension (const matrix_type& m) { //return matrix_type::functor_type::size2 (m.size1(), m.size2 ()); return row_column_major::size2 (m.size1(), m.size2()); } }; }}}} #endif ---------------------//---------------------- boost_mkl_lapack.cpp: namespace ublas = boost::numeric::ublas; #ifdef BOOST_MSVC #pragma warning (disable: 4355) #pragma warning (disable: 4503) #pragma warning (disable: 4786) #endif #define BOOST_UBLAS_USE_EXCEPTIONS #include <iostream> #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/symmetric.hpp> #include <vector> // Intel MKL Lapack #include <mkl/include/mkl_lapack64.h> #include "ublas_matrix.h" // To make life easiertypedef ublas::matrix<double,ublas::row_major> Matrix; typedef std::vector<int> IntVector; template<class M> int getrf(M& a, IntVector& ipiv) { typedef matrix_traits<M> mtraits; typedef vector_traits<IntVector> vtraits; int m = a.size1(); int n = a.size2(); assert(ipiv.size() == (m < n ? m : n)); double *aStorage = mtraits::storage(a); int lda = mtraits::leading_dimension(a); int *ipivStorage = vtraits::storage(ipiv); int info; // return status dgetrf(&m, &n, aStorage, &lda, ipivStorage, &info); return info; } template<class M> int getrs(const M& a, const IntVector& ipiv, M& b, char trans = 'N' ) { typedef matrix_traits<M> mtraits; typedef vector_traits<IntVector> vtraits; int m = a.size1(); int n = a.size1(); assert(ipiv.size() == (m < n ? m : n)); // Note: we need to cast away the const for a and ipiv double *aStorage = const_cast<double*>(mtraits::storage(a)); double *bStorage = mtraits::storage(b); int lda = mtraits::leading_dimension(a); int ldb = mtraits::leading_dimension(b); int *ipivStorage = const_cast<int*>(vtraits::storage(ipiv)); // if b is column major, take size2 (i.e. columns) int nrhs = mtraits::size1(b); int info; // return status dgetrs(&trans, &n, &nrhs, aStorage, &lda, ipivStorage, bStorage, &ldb, &info); return info; } template <typename M> void init_symm (M& m, char uplo = 'f') { size_t n = matrix_traits<M>::size1 (m); for (size_t i = 0; i < n; ++i) { m(i, i) = n; for (size_t j = i + 1; j < n; ++j) { if (uplo == 'u' || uplo == 'U') m(i, j) = n - (j - i); else if (uplo == 'l' || uplo == 'L') m(j, i) = n - (j - i); else m(i, j) = m(j, i) = n - (j - i); } } } // printing: template <typename M> void print_m (const M& m, char const* ch = 0) { if (ch) std::cout << ch << ":\n"; size_t sz1 = matrix_traits<M>::size1 (m); size_t sz2 = matrix_traits<M>::size2 (m); for (std::size_t i = 0 ; i < sz1 ; ++i) { for (std::size_t j = 0 ; j < sz2 ; ++j) std::cout << m(i, j) << " "; std::cout << std::endl; } // std::cout << std::endl; } // printing: template <typename V> void print_v (V const& v, char const* ch = 0) { if (ch) std::cout << ch << ": "; size_t sz = vector_traits<V>::size (v); for (std::size_t i = 0; i < sz; ++i) std::cout << v[i] << " "; std::cout << std::endl; } using std::size_t; void main(void) { size_t n = 3; Matrix a(n, n), acopy(n, n); IntVector ipiv(n); init_symm(a); acopy = a; print_m (a, "A"); // Now factor int status = getrf(a, ipiv); print_v(ipiv, "ipiv"); print_m (a, "A"); // The solution (and the right hand side) are row oriented size_t nrhs = 2; Matrix b(nrhs, n), x(nrhs, n); int i; for(i = 0; i < n; i++) { x(0,i) = (double)i + 1; x(1,i) = (double)i + 4.0; } b = ublas::trans(ublas::prod(acopy, ublas::trans(x))); print_m (b, "b original"); print_m (x, "x original"); status = getrs (a, ipiv, b); // solve from factorization print_m (b, "X"); std::cout << std::endl; // Now try the same for a symmetrix matrix ublas::symmetric_matrix<double, ublas::lower> ml(n, n); init_symm(ml); print_m(ml, "symmetric matrix"); status = getrf(ml, ipiv); print_v(ipiv, "ipiv"); print_m (a, "A"); } You will need your project settings to be such that you link with the Intel lib files and the DLL should be in your path (see Intel MKL documentation). Your link tab in project/settings should contain (the lib directory is set using tools/options, same for the include): mkl_c.lib mkl_p3.lib mkl_lapack.lib You may want to do this in a different namespace than the boost namespace (I actually commented out all the namespace stuff above, but reintroduced it in this posting - if it does not compile, than that's probably the reason). More binds to Lapack still need to be done, but this is a start already. Geert [View Less]

2 1

Intel compiler (7.0), STLport (4.3.5) and Boost?
by Andre du Toit 24 Apr '03

24 Apr '03

Is it possible to build bjam and the boost libraries using the Intel compiler (7.0) in conjunction with STLport(4.3.5) under Windows (2000)? If not, please tell me and do not bother reading the rest of this email! I did manage to build bjam and the boost libraries using msvc-stlport toolset, but we use the Intel compiler in conjunction with STLport for our Windows applications. Now I know I can't just start using the Intel compiler with source using boost libraries which were built with … [View More]

1 0

VC7 internal compiler error in mpl using graph & spirit
by Julius Muschaweck 24 Apr '03

24 Apr '03

Hi, with VC 7.0, with both boost_1_30 and the current CVS, and with both release and debug mode, #include <boost/graph/adjacency_list.hpp> #include <boost/spirit/core.hpp> gives an Internal Compiler Error 1001 at line 52 of h:\jmj\C++\Include\boost_1_30_0\boost\mpl\aux_\preprocessed\msvc70\apply.hpp while the error disappears when changing the order of the include files. I can live with the workaround of course, but maybe someone in charge of mpl would like to go after this. Regards, Julius

1 0

RE: [Boost-Users] Sorting list < shared_ptr < foo > > using std::list::sort()
by Ben Hutchings 24 Apr '03

24 Apr '03

heath_r_davis <1heathdavis(a)msn.com> wrote: > I have experienced some difficulty with sorting lists of type: > > list < shared_ptr < foo > > <snip> You need to specify your own ordering predicate, because shared_ptr<T>::operator< does *not* call T::operator< . Also remember that if operator< is a member function it should be const.

1 0

uBlas matrix - storage class
by geert_ceuppens 24 Apr '03

24 Apr '03

Is there a performance difference between the different storage classes for matrix and vector? If so, which one is the most performant? I could not find any reference to this in the documentation ... :^( Many thanks - Geert

2 1

"Correct" way to return empty shared_ptr?
by dick.bridges＠tais.com 24 Apr '03

24 Apr '03

What is the 'correct' way to return a NULL/empty shared_ptr? For example, this works <snippet> shared_ptr<int> maybe_get_a_pointer() { shared_ptr<int> p; return(p); } </snippet> but seems 'klunky'. I've clearly missed something in the docs/examples somewhere. Can someone point me in the right direction? TIA

2 1

RE: [Boost-Users] Re: pool_allocator problems on VC7.1 (real release)
by Ben Hutchings 23 Apr '03

23 Apr '03

John Harris <john.harris(a)tradingtechnologies.com> wrote: > Ben Hutchings wrote: > > I compiled almost the exact same code: > > > > #include <boost/pool/pool_alloc.hpp> > > #include <map> > > #include <utility> > > > > typedef std::basic_string<char, std::char_traits<char>, > > boost::pool_allocator<char> > t; > > > > int main() > > … [View More]

2 1

Sorting list < shared_ptr < foo > > using std::list::sort()
by heath_r_davis 23 Apr '03

23 Apr '03

I have experienced some difficulty with sorting lists of type: list < shared_ptr < foo > > Here is the expected (sorted) program output: 424238335 596516649 719885386 846930886 1189641421 1649760492 1681692777 1714636915 1804289383 1957747793 Instead, I end up with: 1804289383 846930886 1681692777 1714636915 1957747793 424238335 719885386 1649760492 596516649 1189641421 Below is the code in question: //////////////////////////////////////////////// #include <iostream> #… [View More]

1 0

RE: [Boost-Users] Problems linking with Boost 1.29.0 thread lib, Linux/g++ 3.2.2 -r2
by Ben Hutchings 23 Apr '03

23 Apr '03

subsample <knuarv(a)nith.no> wrote: > Failing to link a program with libboost_thread, even though I supply > the -lboost_thread directive in the makefile. I'm kind of new to > makefiles, having only used Visual C++ in Windows untill recently. I > 've tried changing things around a bit, doesn't help. A minimal test > program I wrote links fine with boost_thread though. My makefile looks > like this: > CC=g++ > CFLAGS=-g > LDFLAGS=-L/home/sub/Libs/alsa/lib -… [View More]

2 1