[boost] Re: A better CopyPtr

From: Kevin Atkinson (kevinatk_at_[hidden])
Date: 2000-03-06 15:15:43

On Mon, 6 Mar 2000, Kevin Atkinson wrote:

>   template <typename T>
>   CopyPtr<T> & CopyPtr<T>::operator= (const CopyPtr<T> & other) 
>   {
>     delete ptr;
>     if (other.ptr != 0) 
>       ptr = new T(*other.ptr);
>     else
>       ptr = 0;
>     return *this;
>   }

Here is a more complicated but more efficient operator=:

  template <typename T> 
  CopyPtr<T> & CopyPtr<T>::operator= (const CopyPtr<T> & other)  
  { 
    if (other.ptr == 0) { 
      delete ptr; 
      ptr = 0; 
    } else if (ptr == 0) { 
      if (other.ptr == 0) 
        ptr = 0; 
      else  
        ptr = new T(*other.ptr); 
    } else { 
      *ptr = *other.ptr; 
    } 
    return *this; 
  } 

---
Kevin Atkinson
kevinatk_at_[hidden]
http://metalab.unc.edu/kevina/