bool OEAssignMDLHydrogens(OEMolBase &mol)
Sets the implicit hydrogen count property of each atom in the molecule by calling OEAssignMDLHydrogens(OEAtomBase*) with the value returned by OEDefaultImplicitHCount. This function returns true if the implicit hydrogen count of any atom in the molecule is changed. It returns false if none of the atoms in the molecule has the implicit hydrogen count changed. The assigned implicit hydrogen count can be accessed by OEAtomBase.GetImplicitHCount method.
bool OEAssignMDLHydrogens(OEAtomBase *atm)
Sets the implicit hydrogen count property of an atom based upon the MDL valence model. This function assumes that the formal charges are correctly set. This function calls the OEAtomBase.SetImplicitHCount method on each atom with the value returned by OEDefaultMDLHCount. This function returns false if the implicit hydrogen count of the atom is not changed. If the charge state of each atom has not been assigned, you should call the OEAssignImplicitHydrogens and OEAssignFormalCharges functions instead.