bool OEIsStandardProteinResidue(const OEHierResidue &res)
bool OEIsStandardProteinResidue(const OEChem::OEResidue &res)
bool OEIsStandardProteinResidue(unsigned int resIdx)

Returns whether the residue referred to is one of: ALA, ARG, ASN, ASP, CYS, GLN, GLU, GLY, HIS, ILE, LEU, LYS, MET, PHE, PRO, SER, THR, TRP, TYR, VAL, ASX, GLX, CYX, CYH, HID, HIE or HIP. Residue indices are provided by OEGetResidueIndex.