Hi:

 I have a code which is suppose to return a pointer to a class
 as follows.. Kindly commnent on  the return value of Sample::interRot.
 thank you

  class Sample {
   public:
     Sample(int n) : len_(n);    //ctor
     ~Sample();                  //dtor
     Sample(const Sample& s);    //copy ctor
     elem *interRot(const int how);
   private:
    elem *list_;
    int len_

 };

  class elem {
   int value;
 };


 elem* Sample::interRot(const int how)
  {
   elem a[how];

    for ( int ch = 0; ch < len_; ++ch)
 a[ch] = list_[ch];
    .
    .
    .
    return(a);

  }
--
sampsona@ifi.uio.no
Seeds, like ideas, don't germinate in concrete

S. D. A. (sampsona@ifi.uio.no) wrote:


:  Hi:
:
:  I have a code which is suppose to return a pointer to a class
:  as follows.. Kindly commnent on  the return value of Sample::interRot.
:  thank you
  (class definitions deleted)
:  elem* Sample::interRot(const int how)
:   {
:    elem a[how];
:
:     for ( int ch = 0; ch < len_; ++ch)
:  a[ch] = list_[ch];
:     .
:     .
:     .
:     return(a);
:
:   }
The array a is local to the function, so returning the pointer is
wrong. Use dynamically allocated array instead.
--
   Esa Pulkkinen                        | C++ programmers do it virtually
   E-Mail:  esap@cs.tut.fi              | everywhere with a class, resulting
   WWW   :  http://www.cs.tut.fi/~esap/ | in multiple inheritance.