notes

========== FUTHARK =============================================================
Return code:
    - 0 on success
    - non-zero or NULL on failure

futhark_context_get_error():
    - Returned string must be free() manually

futhark_context_free()
    - futhark_context_sync() must be called right before

futhark_new_*():
    - Asynchronous -> futhark_context_sync() must be called before using the
      return value.

futhark_values_*()
    - Asynchronous -> futhark_context_sync() must be called before using the
      return value.

futhark_entry_*()
    - Asynchronous -> futhark_context_sync() must be called before using the
      return value.
    - Check return code of both futhark_entry_*() AND futhark_context_sync()

========== MPI =================================================================
MPI_Error_class():
    - Thread-safe
    - Can be called before MPI is initialized
    - Can be called after MPI is finalized

MPI_Error_string():
    - Thread-safe
    - Can be called before MPI is initialized
    - Can be called after MPI is finalized

========== MISC ================================================================
     MPI     |    C     | Futhark
-------------+----------+---------
MPI_C_BOOL   | _Bool    | bool
MPI_INT8_T   | int8_t   | i8
MPI_INT16_T  | int16_t  | i16
MPI_INT32_T  | int32_t  | i32
MPI_INT64_T  | int64_t  | i64
MPI_UINT8_T  | uint8_t  | u8
MPI_UINT16_T | uint16_t | u16
MPI_UINT32_T | uint32_t | u32
MPI_UINT64_T | uint64_t | u64
MPI_FLOAT    | float    | f32
MPI_DOUBLE   | double   | f64