No-op deallocator for boost::shared_ptr

Question

Is there a stock no-op deallocator in Boost to use with boost::shared_ptr for static objects, etc.

I know it's ultra-trivial to write, but I don't want to sprinkle my code with extra tiny functions if there is already one available.

Answer 1

Wouldn't it be cleaner just to take an extra reference so the deallocator is never called? (Although that's still not very clean.)

I can't say that there's no function in Boost which would do the job, but it doesn't sound like something they would want to include.

EDIT: Having read the comments and a little documentation, it boils down to this:

1. Reference leaking. At some point, execute this:

   new shared_ptr( my_global_shared_ptr );
   

   Advantages: conceptually easy. Disadvantages: you are leaking something on the heap.

2. Custom deallocator. Since shared_ptr requires little of the deallocator function, an anonymous identity function like that provided in the other answer would do fine.

   Advantages: leverages Boost and has absolutely no overhead. Disdvantages: requires a little documentation.

3. Non-static global object. If there is a global shared_ptr for your object, that should be the only means of access to it. Replace the declaration of the global with a shared_ptr intialized by new my_class. I think this is best.

Answer 2

Solution uses Boost.Lambda:

#include <boost/shared_ptr.hpp>
#include <boost/lambda/lambda.hpp>

int main()
{
    int *p = new int(5);

    {
        boost::shared_ptr<int> sp(p, boost::lambda::_1);
    }

    delete p;
}

'boost::lambda::_1' creates an empty functor that takes one argument.

You'll probably want to put a //comment in there to let people know why you did it, though.