-----Original Message----- From: "alfC" [alfredo.correa@gmail.com] Date: 24/02/2010 08:24 AM To: boost-users@lists.boost.org Subject: Re: [Boost-users] multi_array : using double** from 3rd party lib
and I wish to pass the "subarray" as a double** argument and call their function .It's not possible, is it?
you have to create the array of pointers: double trace(double** arr){ double ret=0; for(unsigned i=0; i!=4; ++i){ ret+=arr[i][i]; } return ret; } int main(){ boost::multi_array<double, 7> a(boost::extents[2][2][2][2][2][4] [4]); a[1][1][1][1][1][0][0]=8; a[1][1][1][1][1][3][3]=3; double** sarr=new double*[4]; for(unsigned i=0; i!=4; ++i){ sarr[i]=(&a[1][1][1][1][1][i][0]); } std::cout<< trace( sarr ) <<std::endl; //outputs 11 return 0; } , but probably you wanted something simpler.
I am actually able to override their function that takes in a double** data.
Can it work then?
If you can "override" (sic) the function that takes the data, can't you just replace by some multi_array<double, 2>, if there is no pointer arithmetic in the function then that it is easy to do. right? Alfredo _______________________________________________ The function is a virtual member function of a class. It has signature virtual f(double** data, ....) So I can override in my derived class, but then I can only override it with the same signature. creating the array of pointers is what the library does in their default implementation. But for me, I have the data already in the array, so it is a waste of runtime and memory, anyways, you confirmed there is no way around this, thanks very much,