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POChecked iterator not working
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15737187
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0
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1
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4
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2013-04-01T03:17:13.130
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2014-11-20T11:58:23.513
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2014-11-20T11:58:23.513
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1653150
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<p>I'm trying to run the checked iterator example from the c++ programming language (3rd edition) book, but I'm getting errors, and I think I need some help understanding, why I'm getting these errors, I'm getting the code from the book, thanks in advance.</p> <pre class="lang-cpp prettyprint-override"><code>#include <iostream> #include <vector> #include <iterator> #include <exception> #include <cstddef> // using namespace std; template<class Iter> struct iterator_traits{ typedef typename Iter::iterator_category iterator_category; typedef typename Iter::value_type value_type; typedef typename Iter::difference_type difference_type; typedef typename Iter::pointer pointer; typedef typename Iter::reference reference; }; // specialization for pointer //template<class T> struct iterator_traits<T*> //{ // typedef ptrdiff_t difference_type; // typedef T value_type; // typedef T* pointer; // typedef T& reference; // typedef std::random_access_iterator_tag iterator_category; //}; template<class Cat, class T, class Dist=ptrdiff_t, class Ptr=T*, class Ref=T&> struct iterator{ typedef Cat iterator_category; typedef T value_type; typedef Dist difference_type; typedef Ptr pointer; typedef Ref reference; }; template<class Ran> typename iterator_traits<Ran>::difference_type dist_helper(Ran first, Ran last, random_access_iterator_tag) { return last-first; //rely on random access } template<class In > typename iterator_traits<In>::difference_type distance(In first, In last) { return dist_helper(first, last, iterator_traits<In>::iterator_category()); } //Code template <class Cont, class Iter=typename Cont::iterator> class Checked_iter : public iterator_traits<Iter>{ //deriving from iterator_traits Iter curr; Cont* c; //.... public: void valid(Iter p) { if ( c->end() == p) return; for(Iter pp= c->begin(); pp != c->end(); ++pp){ if (pp==p) return; } throw std::out_of_range("out of range"); } friend bool operator==(const Checked_iter& i, const Checked_iter& j) { return i.c == j.c && i.curr == j.curr; } //no default initialzer //use defaul t copy constructor and cop assignment. Checked_iter(Cont& x, Iter p):c(&x), curr(p) {valid(p);} //Error:Unkown type name "reference" reference operator*() { if (curr == c->end()) throw std::out_of_range("out of range"); return *curr; } //Error:Unkown type name "pointer" pointer operator->() { return &*curr; // checked by * } //Error:Unkown type name "difference_type" Checked_iter operator+(difference_type d ) // for random access iterators only { if(c->end() - curr <= d ) throw std::out_of_range("out of range"); return Checked_iter(c ,curr+d ); } //Error:Unkown type name "difference_type" reference operator[](difference_type d ) // for random access iterators only { if (c->end() - curr <= d) throw std::out_of_range("out of range"); return c[d]; } Checked_iter& operator++() // prefix ++ { if (curr == c->end()) throw std::out_of_range("out of range"); ++curr; return *this ; } Checked_iter& operator++(int) { Checked_iter tmp= *this; ++*this; //Checked by prefix ++ return tmp; } Checked_iter& operator--() //prefix-- { if(curr == c->begin()) throw std::out_of_range("out of range"); --curr; return *this; } Checked_iter& operator--(int) //postfix { Checked_iter tmp=*this; --*this; //checked by prefix -- return tmp; } //Error:Unkown type name "difference_type" difference_type index() {return curr-c.begin();} //random access only Iterator unchecked() {return curr;} //+-< }; template<class Cont, class Iter> Checked_iter<Cont,Iter>make_checked(Cont& c, Iter i) { return Checked_iter<Cont, Iter>(c,i); } template<class Cont>Checked_iter<Cont,typename Cont::iterator>make_checked(Cont& c) { return Checked_iter<Cont, typename Cont::iterator>(c,c.begin()); } void f_count(vector<int>& vec) { int count=0; try{ Checked_iter<vector<int>> p(vec, vec.begin()); while(true){ ++p; ++count; } } catch(out_of_range){ cout<<"overrun after"<<count<<"tries\n"; } } void test_f(){ int a[] = {0,1,2,3,4,5,6,7,8,9}; vector<int> l(a, a+sizeof(a)/sizeof(int)); print_v(l); f_count(l); } void print_v(vector<int>vec) { for(aut i=vec.begin();i != vec.end(); ++i) cout<<*i<<" "; } int main() { test_f(); return 0; } </code></pre> <p>I'm getting <code>unknown type name</code> error for <code>reference</code>, <code>pointer</code> and <code>difference_type</code>.</p>
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<c++><templates><exception-handling><c++11><iterator>
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Checked iterator not working
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