The comparison operators are prototyped as follows:
int MPI::<CLASS>::operator==(const MPI::<CLASS>& data) const
bool
int MPI::<CLASS>::operator!=(const MPI::<CLASS>& data) const
bool
The member function operator==() returns true only when the handles reference the same internal MPI-/ object, false otherwise. operator!=() returns the boolean complement of operator==(). However, since the Status class is not a handle to an underlying MPI-/ object, it does not make sense to compare Status instances. Therefore, the operator==() and operator!=() functions are not defined on the Status class.
MPI-Standard for MARMOT