[Boost-users] shared_memory_object constructor

Subject: [Boost-users] shared_memory_object constructor
From: Just C (justachap_at_[hidden])
Date: 2010-03-24 03:58:00

I find shared_memory_object constructor semantics to be
rather inconvenient for embedding it into another
class.

Consider the following

class A
{
  public:
  A(int type) : shm_(pass params to the shared_memory_object ctor)
  {

  }
  private:
  shared_memory_object shm_;
};

If my class A is such that a shared_memory_object needs to be called with
either create_only or open_only based on
the type passed to A's constructor, I  can't do it easily.

i.e. some thing like
A(int type) : shm_(type ==  something ? create_only : open_only) {}

This won't work because create_only & open_only are different types & this
will call 2 different overloaded constructors,
hence the above code will not compile.

Alternatives here are
1) make A a templated class instead of having type as a ctor param.
i.e.
template <class T>
class A
{
 public:
 A() : shm_(T(), other params) {}
};

then use
A<create_only> a;
A<open_only> b;

OR

2) Keep a  shared_memory_object ptr inside non-templated class A instead of
an actual object
and create it dynamically.

Assuming, I don't want to use either of these options, is there any other
nifty trick anyone can think of to achieve what I want to do?