C++ Primer, Fifth Edition

14.7. Member Access Operators

The dereference (*) and arrow (->) operators are often used in classes that represent iterators and in smart pointer classes (§ 12.1, p. 450). We can logically add these operators to our StrBlobPtr class as well:

class StrBlobPtr {public:    std::string& operator*() const    { auto p = check(curr, "dereference past end");      return (*p)[curr];  // (*p) is the vector to which this object points    }    std::string* operator->() const    { // delegate the real work to the dereference operator     return & this->operator*();    }    // other members as before};

The dereference operator checks that curr is still in range and, if so, returns a reference to the element denoted by curr. The arrow operator avoids doing ...