Re: non destructable pointer

Pete Becker <>
12 Jul 2006 19:04:47 -0400
Hotlips wrote:

In our current system we have a need to hand out pointers, either as
interface pointers or arrays of pointers (we cannot directly hold
references in an STL container). Some of the pointers will be pointing
to statically allocated (not on the heap) objects, meaning a
Boost.SharedPointer or just a simple "delete" is a no-go!

TR1's shared_ptr (as well as Boost's, on which it was based) can be
used. All you need to do is provide a deleter object that doesn't do

struct MyTy
// whatever

struct null_deleter
void operator()(MyTy*) {}

int main()
     MyTy obj;
     shared_ptr<MyTy> ptr(&obj, null_deleter());
     return 0;

When the shared_ptr object goes out of scope its destructor calls the
deleter object's function call operator, passing the address of its
controlled resource. Since the body of the function call operator is
empty, nothing happens to the resource until its own destructor runs.

For more details, see chapter 2 of my book, "The C++ Standard Library
Extensions," due in bookstores in a couple of weeks. It covers all of TR1.

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