E value
) Adds value
into the set. Returns true
if value
was added to the set.
If value
already exists, the set is not changed and false
is returned.
Source
/**
* Adds [value] into the set. Returns `true` if [value] was added to the set.
*
* If [value] already exists, the set is not changed and `false` is returned.
*/
bool add(E value);