On 10/14/10 5:32 AM, Steffen Neumann wrote: > Hi > > On Thu, 2010-10-14 at 11:56 +0100, Noel O'Boyle wrote: >> memcpy((char*)origCoords,(char*)_mol.GetCoordinates(),sizeof(double)*_ncoords); >> >> However, both origCorrds and _mol.GetCoordinates are (double*) not >> (char*). Is this not an error? > No, a pointer has X bytes regardless whether it points > to a char, double (or void :-) > > An it will copy _ncoords times the space required for sizeof(double). > The error would be if it used sizeof(char).
Right, but ... This is not a very good way to do this. It assumes that _mol.GetCoordinates() is going to return an array of double exactly _ncoords long. If someone changes the data structures, how would they know to look here to find this and fix it too? It's a time bomb, especially if there is a lot of this sort of thing around. The real question is whether the code ensures that origCoords was allocated to be at least as large as sizeof(double)*_ncoords. This is an example of using C coding style in a C++ program. The proper way to do it would be to create object classes so that you could just use a constructor or '=' operator to copy the coordinates. Craig ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ OpenBabel-Devel mailing list OpenBabel-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openbabel-devel
