Actually, the second case can be fixed with: multi_array<triangular_matrix<double, lower> , A_dim> A; A.resize(extents[2][2][2][2]); But still, for the developer, the code for the second case should not compile then. Max On Thu, Aug 12, 2010 at 1:16 PM, Max S. Kaznady <max.kaznady@gmail.com> wrote:
Hello, I just noticed a strange runtime error, and I think that it should be addressed by the developers. Consider the following seemingly equivalent statements, in terms of functionality: using namespace boost::numeric::ublas; using namespace boost::multi_array; const unsigned A_dim = 4; multi_array<triangular_matrix<double, lower> , A_dim>::extent_gen extents; 1) multi_array<triangular_matrix<double, lower> , A_dim> A(extents[2][2][2][2]); 2) multi_array<triangular_matrix<double, lower> , A_dim> A; A = multi_array<triangular_matrix<double, lower> , A_dim>(extents[2][2][2][2]);
Add either statement 1 or 2. Both compile just fine with GCC 4.4, but the second statement, last line, produces a runtime error:
main: /usr/local/boost/include/boost/multi_array/multi_array_ref.hpp:487: boost::multi_array_ref<T, NumDims>& boost::multi_array_ref<T, NumDims>::operator=(const ConstMultiArray&) [with ConstMultiArray = boost::multi_array<boost::numeric::ublas::triangular_matrix<double, boost::numeric::ublas::basic_lower<long unsigned int>, boost::numeric::ublas::basic_row_major<long unsigned int, long int>, boost::numeric::ublas::unbounded_array<double, std::allocator<double>
, 4ul, std::allocator<boost::numeric::ublas::triangular_matrix<double, boost::numeric::ublas::basic_lower<long unsigned int>, boost::numeric::ublas::basic_row_major<long unsigned int, long int>, boost::numeric::ublas::unbounded_array<double, std::allocator<double>
, T = boost::numeric::ublas::triangular_matrix<double, boost::numeric::ublas::basic_lower<long unsigned int>, boost::numeric::ublas::basic_row_major<long unsigned int, long int>, boost::numeric::ublas::unbounded_array<double, std::allocator<double> , long unsigned int NumDims = 4ul]: Assertion `std::equal(other.shape(),other.shape()+this->num_dimensions(), this->shape())' failed.
I KNOW that I can resolve the issue with shared_ptr, having multi_array store shared pointers to the matrix A. However, if I understand correctly, then shouldn't the second statement either not compile or compile and work fine? From what I understand the added functionality of multi_arrays is that they can store other arrays, maybe I'm wrong?
Thanks, Max