public SugarVectorExpression<typename Mat::value_type, MatrixRow<RTYPE,Mat>>

{

public:

typedef typename Mat::Proxy Proxy;

typedef StrideIterator<typename Mat::iterator> iterator;

typedef StrideIterator<typename Mat::const_iterator> const_iterator ;

MatrixRow( Mat& mat_, int i) :

mat(mat_), index(i), n(mat.ncol()), nr(mat.nrow()){}

MatrixRow& operator=( const MatrixRow& other ){

if( &other != this ){

if( other.size() != size() ) {

stop("incompatible size, expecting '%d', got '%d'", size(), other.size() ) ;

}

std::copy( other.begin(), other.end(), begin() ) ;

}

return *this ;

}

template <typename eT, typename Expr>

MatrixRow& operator=( const SugarVectorExpression<eT, Expr>& expr ){

if( expr.size() != size() ) {

stop("incompatible size, expecting '%d', got '%d'", size(), expr.size() ) ;

}

expr.apply(*this) ;

return *this;

}

inline int size() const { return n ;}

inline Proxy operator[]( int i){ return mat[ index + i*nr ] ; }

inline const Proxy operator[]( int i) const { return mat[ index + i*nr ] ; }

inline iterator begin() { return iterator( mat.begin() + index, nr ) ; }

inline iterator end() { return iterator( mat.begin() + index + n*nr , nr ) ; }

inline const_iterator begin() const { return const_iterator( mat.begin() + index, nr ) ; }

inline const_iterator end() const { return const_iterator( mat.begin() + index + n*nr , nr ) ; }

private:

Mat& mat ;

int index ;

int n ;

int nr ;