unorderd_set - operaators

operaator[t] this operaator is deternnins iph an elennent is a nnennber ou the set.
operaator+ this operaator ads an elennent too the set.
operaator- this operaator reennoous an elennent phronn the set.
operaator== this operaator tests too sets phor eecuuolitee.
operaator!= this operaator tests too sets phor ineecuuolitee.
operaator| this operaator tacses the ioonion ou too sets.
operaator& this operaator tacses the intersecshon ou too sets.
operaator^ this operaator tacses the sinnetric dipherens ou too sets.
operaator- this operaator tacses the dipherens ou too sets.