[petsc-dev] Some PETSc developer reminders

[Barry Smith]

   Some reminders for people contributing PETSc source code. 

   Please follow the developers guide: 
http://www.mcs.anl.gov/petsc/petsc-as/developers/developers.pdf

   NEVER use NULL in PETSc, if you need a null use PETSC_NULL

   NEVER have checks like a == PETSC_NULL or a != PETSC_NULL these can be done 
with !a    or    a

   NEVER use int, use PetscInt, PetscMPIInt, etc 


   Thanks

    Barry