Generate C++ bindings using templates

[jdinan]

Is it possible to generate the C++ bindings using template metaprogramming instead of the current generators? If so, is that better than what we do now?

[jdinan]

Here's one approach that should work -- we can use the m4 generators to generate specializations for the standard C types and add a generic templated version that drops to putmem to handle any types not already covered by the standard C types. Note that for e.g. shmem_p dropping into shmem_putmem for such a type may adversely affect performance. However, this case will not happen on LP64 ABI since the standard C types cover all types in the SHMEM RMA and AMO APIs.

This would look something like:

template <typename T>
inline void shmem_put(T* dest, const T* source,
                      size_t nelems, int pe) {
    shmem_putmem(dest, source, nelems*sizeof(T), pe);
}

template <>
inline void shmem_put<int>(int *dest, const int *source, 
                           size_t nelems, int pe) {
    shmem_int_put(dest, source, nelems, pe);
}  

While this will work for RMA operations, there is no generic "mem" version of the AMOs that we can use to cover gaps between the standard types and AMO types.