#include "petscsys.h" PetscErrorCode PetscOptionsEnum(const char opt[],const char text[],const char man[],const char *const *list,PetscEnum currentvalue,PetscEnum *value,PetscBool *set)
| opt | - option name | |
| text | - short string that describes the option | |
| man | - manual page with additional information on option | |
| list | - array containing the list of choices, followed by the enum name, followed by the enum prefix, followed by a null | |
| currentvalue | - the current value; caller is responsible for setting this value correctly. Normally this is done with either |
PetscOptionsEnum(..., obj->value,&object->value,...) or
value = defaultvalue
PetscOptionsEnum(..., value,&value,&flg);
if (flg) {
| value | - the value to return | |
| set | - PETSC_TRUE if found, else PETSC_FALSE |
list is usually something like PCASMTypes or some other predefined list of enum names
If the user does not supply the option at all value is NOT changed. Thus you should ALWAYS initialize value if you access it without first checking if the set flag is true.
The default/currentvalue passed into this routine does not get transferred to the output value variable automatically.