C + +: About Set

1. Initialization of the Set

The set can be initialized like this:

set<int1,2,3  };   set<int1,2,3 };  

When the set is initialized, duplicate elements appear:

set<int1,2,3,3,3  };   set<int1,2,3,3,3 };  

The extra repeating element is deleted when it is stored, and if printed, the set has only three elements.

2. About Set iterators

Because set does not define a + and-operation, there is no way to specify iterators in a set.iterator+n way, such as this

Set<int> an_set1{2,3,4,5,6};

Vector<int> An_vector2 (An_set1.begin () +1, An_set1.end ());

Such an operation is wrong. However, set defines the iterator's self-plus + + and auto-subtract + +, so it is possible to iterate over the set element with an iterator.

C + +: About Set