Several examples in the EXAMPLE subdirectories use MPI constants such as MPI_THREAD_SINGLE in C case statements. This leads to compiler errors with certain MPI implementations.

I have written a forwarding MPI implementation MPItrampoline. In this implementation, MPI constants such as MPI_THREAD_SINGLE are regular integer constants and are not known at compile time. Consequently, they cannot be used in a C case statement. (The MPI standard 4.0 lists in section 2.5.4 which MPI constants can be used in case statements.)

Could you change you code to use if statements instead of a switch statement? I will open a pull request for this.