_``` (```MPI_CHECK```, ```MPI_ASSERT```...). The first argument is the rank for which they are checked, and the second is the usual expression to check.

## The main entry points and mpi reporters

You need to launch the unit tests with an ```mpirun``` or ```mpiexec``` command:
```
mpirun -np 2 unit_test_executable.exe
```

```doctest::mpi_init_thread()``` must be called before running the unit tests, and ```doctest::mpi_finalize()``` at the end of the program. Also, using the default console reporter will 