description:
"An aggregate is an array or a class with no user-declared constructors, no private or protected non-static data members, no base classes, and no virtual functions." Aggregates can be initialized by "brace-enclosed, comma separated list of initializer-clauses for the members of the aggregate, written in increasing subscript or member order." Static data members are skipped during this type of initialization so 3.14 initializes d and not sd in this example "If there are fewer initializers in the list than there are members in the aggregate, then each member not explicitly initialized shall be value-initialized". So in this example i is value-initialized to 0.
