I am under the impression that one of the (perhaps implicit) requirements of
the C++ STL is that std::vectors are stored in contiguous memory. So the
below code should work with all conformant C++ compilers.
Vince Virgilio
> -----Original Message-----
> From: Vishal Sahay [mailto:vsahay_at_[hidden]]
> Sent: Tuesday, April 22, 2003 9:17 PM
> To: sbcair; General LAM/MPI mailing list
> Subject: Re: LAM: MPI datatypes
>
>
> It is possible to send STL vector<double> in the manner shown
> in the second code.
>
> The traditional C way of doing it would be:
>
> void
> foo(int array_len)
> {
> double *a;
> a = malloc(sizeof(double) * array_len);
>
> /* do some work on a */
>
> MPI_Send(a, array_len, MPI_DOUBLE, dest, tag, comm);
> }
>
> Using STL vectors, the code would be:
>
> void
> foo(int array_len)
> {
> vector<double> a;
>
> /* do some work on a */
>
> MPI_Send(&a[0], array_len, MPI_DOUBLE, dest, tag, comm);
> }
>
> This may not necessarily work with all compilers, but so far
> has worked for most of them. Note that this seems to work
> only for STL vectors and not STL lists or other STL stuffs.
>
> Infact it would work for vector<T> where T is just any common
> datatypes or a simple struct.
>
> Hope this helps...
>
> -Vishal Sahay
> ===================================================================
> (Graduate Student, CS Dept. Open Systems Lab
> Indiana University, Bloomington) Make Today A LAM/MPI Day :)
> http://cs.indiana.edu/~vsahay http://www.lam-mpi.org
> ===================================================================
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