A formal operational semantics for C++ object construction and destruction

• list(A) is the set of all lists having their elements in A • nil is the empty list • a :: q is the list starting with an element a and continuing with the tail list q • q − is the append (list concatenation) operator: for any list l, we have nil q −l def. l and (a :: q) q −l def. a :: (q q −l). • lterf (l) is the lter operator, recursively de ned as follows: lterf ( ) = and lterf (a :: q) = { a :: lterf (q) if f(a) = true lterf (q) otherwise • rev(l) is the reverse of the list l, i.e. the list of elements of l given in the reverse order of l. That is, rev( ) = and rev(a :: q) = rev(q) q −a :: . • length(l) is the length of a list l: length(nil) def. 0 and length(a :: l′) def. 1 + length(l′)