First draft of SHTs in Python wrapper

libsharp/sharp_lowlevel.h

@@ -239,6 +239,30 @@ void sharp_execute (sharp_jobtype type, int spin, void *alm, void *map,
 void sharp_set_chunksize_min(int new_chunksize_min);
 void sharp_set_nchunks_max(int new_nchunks_max);
 
+
+typedef enum { SHARP_ERROR_NO_MPI = 1,
+               /*!< libsharp not compiled with MPI support */
+              } sharp_errors;
+
+/*! Works like sharp_execute_mpi, but is always present whether or not libsharp
+    is compiled with USE_MPI. This is primarily useful for wrapper code etc.
+
+    Note that \a pcomm has the type MPI_Comm*, except we declare void* to avoid
+    pulling in MPI headers. I.e., the comm argument of sharp_execute_mpi
+    is *(MPI_Comm*)pcomm.
+
+    Other parameters are the same as sharp_execute_mpi.
+
+    Returns 0 if successful, or SHARP_ERROR_NO_MPI if MPI is not available
+    (in which case nothing is done).
+ */
+int sharp_execute_mpi_maybe (void *pcomm, sharp_jobtype type, int spin,
+  void *alm, void *map, const sharp_geom_info *geom_info,
+  const sharp_alm_info *alm_info, int ntrans, int flags, double *time,
+  unsigned long long *opcnt);
+
+
+
 /*! \} */
 
 #ifdef __cplusplus