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POC++: Using any iterator type in a faux-STL class?
 

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  1. POC++: Using any iterator type in a faux-STL class?
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    <p>I'm creating a container class very similar to a vector (class project), and have defined an iterator subclass. One of the ctors takes two iterator arguments, and builds the data structure (doubly linked list) using the half-open range they represent. </p> <p>The code below (almost) works for cases when insert(iterator, iterator) is called with two iterators of type Sol::iterator (for some reason, *ita always points to the right values, but the insert(*ita) call doesn't seem to add the value??). The (larger) problem is that the insert call needs to work for all iterator types (ex. vector::iterator), and I haven't been able to track down how to make that work. I've tried typedef / typename T::iterator iterator, but the quietest g++ has been was with 'typename T::iterator iterator', and it returns </p> <pre><code>g++ ex1.cc -o sol -Wall -Wextra -ansi -pedantic In file included from ex1.cc:1:0: Sol.h:87:16: error: expected ‘)’ before ‘ita’ ex1.cc:109:5: error: expected ‘}’ at end of input In file included from ex1.cc:1:0: Sol.h:84:3: error: expected unqualified-id at end of input make: *** [ex1] Error 1 </code></pre> <p>which doesn't make much sense; at least to me. Here's the broad strokes:</p> <pre><code>template &lt;class T, int find_val = 1, class Compare = std::less&lt;T&gt; &gt; class Sol{ public: typedef unsigned int size_type; //typedef'ing class variable types typedef T key_type; typedef T value_type; //typename T::iterator iter; private: struct node{ //Used as 'links' in the chain that is the doubly linked list T data; node *prev; node *next; }; node *head, *tail; //The head and tail of the dll int find_promote_value; //How much should find() shift a value? public: class iterator{ private: node *no; friend class Sol; iterator(node *p) : no(p){ } public: iterator() : no(0){ } iterator operator++(){ //Preincrement no = no-&gt;next; return *this; } iterator operator++(int){ //Postincrement iterator temp = *this; ++*this; return temp; } iterator operator--(){ //Predecrement no = no-&gt;prev; return *this; } iterator operator--(int){ //Postdecriment iterator temp = *this; --*this; return temp; } T operator*(){ return no-&gt;data; } T *operator-&gt;(){ return &amp;no-&gt;data; } bool operator==(const iterator &amp;rhs){ return no == rhs.no; } bool operator!=(const iterator &amp;rhs){ return no != rhs.no; } }; Sol() : head(0), tail(0), find_promote_value(find_val){ } Sol(const Sol &amp;rhs) : head(rhs.head), tail(rhs.tail), find_promote_value(rhs.find_promote_value){ } typename T::iterator iterator; Sol(iterator ita, iterator itb){ //Sol.h::87. Problem line while (ita != itb){ iterator itr = insert(*ita); std::cout &lt;&lt; "Inserting " &lt;&lt; *ita &lt;&lt; ",printout: " &lt;&lt; *itr &lt;&lt;"\n"; //dump(); ++ita; } } ~Sol(){ clear(); } iterator insert(T input){ node *n = new node; n-&gt;next = NULL; n-&gt;prev = tail; n-&gt;data = input; if(!tail){ head = n; tail = n; } else{ tail-&gt;next = n; tail = n; } return iterator(tail); } }; </code></pre>
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    1. USKyle Smith
    1. USKyle Smith
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      1. POC++: Using any iterator type in a faux-STL class?
      1. USSDEZero
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    1. CONo; it's a ctor, so I don't think I need it?
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      1. POC++: Using any iterator type in a faux-STL class?
      1. USKyle Smith
    2. COI am sorry for the noise. I did closely observe that `Sol` is class type.
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      1. POC++: Using any iterator type in a faux-STL class?
      1. USMahesh
    3. CONo sweat, man; I appreciate having the eyes on the problem.
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      1. POC++: Using any iterator type in a faux-STL class?
      1. USKyle Smith
 

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