const Type *SrcTy, ///< SrcTy of 1st cast
const Type *MidTy, ///< DstTy of 1st cast & SrcTy of 2nd cast
const Type *DstTy, ///< DstTy of 2nd cast
const Type *SrcTy, ///< SrcTy of 1st cast
const Type *MidTy, ///< DstTy of 1st cast & SrcTy of 2nd cast
const Type *DstTy, ///< DstTy of 2nd cast