I've noticed that recent commits are now accessing PetscObject internals like this obj->hdr.comm obj->hdr.type_name I would really prefer to not do that, and instead use the more verbose ((PetscObject)obj)->comm ((PetscObject)obj)->type_name If this is really disgusting, perhaps we should define and use some (private?) macros like below. By far, 'comm', 'type_name', and 'prefix' are the more commonly accessed members when implementeing Vec, Mat, KSP, PC, etc. PetscCOMM(obj) PetscTYPE(obj) PetscPREFIX(obj) -- Lisandro Dalc�n --------------- Centro Internacional de M�todos Computacionales en Ingenier�a (CIMEC) Instituto de Desarrollo Tecnol�gico para la Industria Qu�mica (INTEC) Consejo Nacional de Investigaciones Cient�ficas y T�cnicas (CONICET) PTLC - G�emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594