714 struct _Unary: _Expr<_Unary<LHS,DerivedOp>>  struct
716     using Scalar = typename traits<LHS>::Scalar;
718     using Vector = typename traits<LHS>::Vector;
720     _Unary(const LHS &lhs,  in _Unary()  function
725     _Unary(const _Unary &other):  in _Unary()  argument
729     _Unary(LHS &&other):  in _Unary()  function
737     vector_length_t length() const {  in length()
743     vector_length_t rows() const {  in rows()
749     vector_length_t columns() const {  in columns()
755     Scalar const operator[](const index_t i) const {  in operator []()
761     Scalar const operator()(const index_t r,const index_t c) const  in operator ()()
772     Vector const vector_op(const index_t i) const  in vector_op()
794     Vector const matrix_op(const index_t r,const index_t c) const  in matrix_op()
809     const LHS lhs_;
810     const _UnaryOperator<Scalar,DerivedOp> op_;