-----Original Message----- From: "Riccardo Murri" [riccardo.murri@gmail.com] Date: 08/12/2010 01:50 PM To: boost-users@lists.boost.org Subject: Re: [Boost-users] mpi: sending/receiving different types

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2. the root sends directly a reference to a base class of anything sendable, then the receivers construct the derived classes on reception with broadcast. The T is then the base class type.

There's a risk of slicing here, i.e., if you pass a reference to a base class, only the base class data will be serialized and received.

As far as I understand, Boost.Serialization (hence Boost.MPI) will do the correct thing if you use *pointers* instead: i.e., you send a pointer to a (derived) class and you receive it through a pointer to the base class. (Beware: I have not checked!)

Does Boost.Serialization/MPI construct an object on the heap when it deserializes? e.g. master: base* b = &derived; broadcast( world, b, 0 ); slave: base* b; broadcast( world, b, 0 ); /// does this create the appropriate derived class on the heap, and make b point to it? Is this what you meant? Another question, the base struct contains a double and 2 char[8] fields, but also a virtual function. Does this mean it shouldn't be set as being a MPI data type because of its polymorphism? Thanks,