I believe there is a typo in Stroustup's book, third edition page 368. Could someone confirm?
سؤال
I believe there's a typo on this code snippet extracted from Stroustup's book, at its page 368 :
template <class X> class std::auto_ptr
{
template <class Y> struct auto_ptr_ref { /* ... */ }; // helper class
X * ptr;
public :
typedef X element_type;
explicit auto_ptr(X* p =0) throw() { ptr = 0; }
auto_ptr (auto_ptr& a) throw() { ptr = a.ptr; a.ptr = 0; } // note: not const auto_ptr&
/* ... */
};
Shouldn't
explicit auto_ptr(X* p =0) throw() { ptr = 0; }
be
explicit auto_ptr(X* p =0) throw() { ptr = p; }
instead ?
المحلول
The errata for the book makes some changes:
Chapter 14:
pg 367-368 A recent standards change modified the definition of auto_ptr. Please replace the last paragraph on page 367 and page 368 ...
نصائح أخرى
I've looked in that book however I have a newer version, which has some extra pages.
Anyhow, that code looks correct because it's saying p = 0 and by saying ptr = p is the same thing with ptr = 0.
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