Ion, thanks for your answer. I did actually try to explain the matter from the RAII standpoint. I think my colleague now understands. As for the constructor. Perhaps, you could add a helper function: template< typename T > void make_shared_memory_object( shared_memory_object& shmem , std::string& name , std::size_t size ) { shared_memory_object tmp( T(), name.c_str(), size ); tmp.swap( shmem ); } Regards, Christian 2009/8/27 Ion Gaztañaga <igaztanaga@gmail.com>:

Christian Henning escribió:

...

Hi there, a colleague of mine is questioning the design decisions in the shared_memory_object class. The assignment operator and copy constructor are private. Why?

Because the class own a unique resource just like a file. Is fstream copyable? No, movable (in c++0x) just like shared_memory_object. What should the copy constructor do?

Also the constructor takes a type

...

instead of a value as the first parameter. In his eyes it makes it very inflexible since the creation of or attaching to shared_memory area has to known at compile time.

Ok, this is debatable, because with move semantics you can write:

shared_memory_object obj(create?                        shared_memory_object(create_only, ...):                        shared_memory_object(open_only, ...));

or

shared_memory_object shm;

if(create){   shared_memory_object tmp(create_only);   tmp.swap(shm); } else{   shared_memory_object tmp(open_only);   tmp.swap(shm); }

Best,

Ion

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