Small help on doubly linked list.

This is a discussion on Small help on doubly linked list. within the C++ Programming forums, part of the General Programming Boards category; Sorry for the trouble, but this should be pretty trivial. Some of the code Code: list.h: namespace List { struct ...

  1. #1
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    Small help on doubly linked list.

    Sorry for the trouble, but this should be pretty trivial. Some of the code

    Code:
    list.h:
    namespace List
    {
      struct list_t {
        std::string name;
        list_t* prev;
        list_t* next;
      };
      list_t* create(std::string name);
      list_t* add(list_t* ll, std::string name);
    }
    
    list.c:
    
    List::list_t* List::create(std::string name)
    {
      List::head = new List::list_t;
      head->prev = NULL;
      head->next = NULL;
      head->name = name;
    
      return List::head;
    }
    
    List::list_t* List::add(List::list_t* list, std::string name)
    {
      if(list == NULL)
      {
        List::list_t* new_list = List::create(name);
    
        return new_list;
      }
    
      list->next = List::add(list->next, name);
      return list;
    }
    
    main.c
    List = List::add(NULL, "CPlusPlus");
    List = List::add(List, "C");
    cout << list->name /*works*/
    cout << list->next->name /*doesn't work, program crashes here =(*/
    For some reason, the list is still empty after the first head. It's probably because the newly made list is a local variable when it's made and when it's returned the local variable is destroyed?

    Thanks.

  2. #2
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    Er I managed to fix the problem. Sorry for the trouble. Couldn't find a way to delete/lock the topic though...

  3. #3
    C++まいる!Cをこわせ! Elysia's Avatar
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    You don't need to. Others can benefit from your problem and learn from it.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  4. #4
    Cat without Hat CornedBee's Avatar
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    They could benefit even more if you could post the solution you found.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

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