add abstract method
Adds value
to the set.
Returns true
if value
(or an equal value) was not yet in the set.
Otherwise returns false
and the set is not changed.
Example:
enum Numbers {one, two, three;}
var set = EnumSet<Numbers>.of(Numbers.values, [Numbers.two]);
var added = set.add(Numbers.one);
print(added); // true
added = set.add(Numbers.two);
print(added); // false
print(set); // (Numbers.one, Numbers.two)
Implementation
@override
bool add(T value);