c++ variable initialization in a class to send it using mpi

Question

Hello Everybody,

I got stuck in a programming task. I want the elements of my stl vector to be placed in a

contiguous memory to send it with MPI_Send() routine.

here is an example:

class Tem
{

//...
private: 
 vector<double> lenghtVector (4500);//this gives a compilation error but I need to have a fixed sized vector

};

how can I have a vector with a serial memory of should I do something else?

Thanks. Kindest Regards.

SRec

Answer 1

The elements of a vector are stored contiguously according to C++ Standard (23.2.4/1). To resize it you could use appropriate constructor in the initializer list of Tem class.:

class Tem
{
  Tem() : lenghtVector(4500) {};
private: 
 vector<double> lenghtVector;
};

Answer 2

nevermind (question was changed while answering)

Answer 3

vector will do what you want, as the data is guaranteed to be contiguous. Use &(v[0]) to get a pointer that you can pass to MPI_Send().

If you don't need the dynamic sizing of vector, you might want to look at the Boost Array class. The size is fixed at compile time, but it is an STL compatible container, so you get begin(), end(), size(), etc.