Member predicate ForStmt::getAnIterationVariable
Gets a variable that is used as an iteration variable: it is defined,
updated or tested in the head of the for
statement.
This only returns variables that are quite certainly loop variables; for complex iterations, it may not return anything.
More precisely, it returns variables that are both accessed in the
condition of this for
statement and updated in the update expression
of this for statement but may be initialized elsewhere.