[petsc-dev] declaring argument as const basic type in PETSc

[Barry Smith]

   Some declarations of the form 

extern PetscErrorCode SAAddData(SA arr, const PetscInt len, const PetscInt *ia, const PetscScalar *wa, const PetscInt *ja);

have crept into PETSc.  const PetscInt len

Do we want to have such beasties? What purpose do they serve? 

My understanding is that it is contaminating the entire code (because of the extern PetscErrorCode SAAddData(SA arr, const PetscInt len, const PetscInt *ia, const PetscScalar *wa, const PetscInt *ja); with the knowledge that internally the subroutine never changes the value of the stack variable function which is the opposite of encapsulation. What am I missing? Is this just stupid C syntax, is there a better way?

   Thanks

    Barry