template meta programming - Implementing the A(:,k)=b; Matlab-like syntax in a C++ matrix library -

i have developed expression templates-based c++ matrix class of own. have overloaded () operator can read or write element matrices as, example,

cout << a(i,j) << endl; 

and

a(i,j)=b; 

respectively. have implemented range class enable matlab-like reads as

cout << a(range(3,5),range(0,10)) << endl; 

the template matrix class exemplified as

template <typename outtype> class matrix {     private:         int rows_;          //number of rows         int columns_;       //number of columns         outtype *data_;     //row-major order allocation     public:          // --- access operators          inline outtype & operator()(const int i, const int j)       { return data_[idx2r(i,j,getcolumns())]; }         inline outtype   operator()(const int i, const int j) const { return data_[idx2r(i,j,getcolumns())]; }          // --- subexpressions - range range         inline expr<submatrixexpr<const outtype*,outtype>,outtype> operator()(range range1, range range2)         {   typedef submatrixexpr<const outtype*,outtype> sexpr;                  return expr<sexpr,outtype>(sexpr(data_,rows_,columns_,range1.numelements_,range2.numelements_,range1.start_,range1.step_,range2.start_,range2.step_),                         range1.numelements_,range2.numelements_);          } } 

i enable matlab-like assignments as

a(range(3,5),range(0,10))=b; 

where b appropriate matrix.

i think that, achieve matlab-like syntax above, 2 possibilities be

1. overloading () operator, returns array of pointers, , overloading = operator latter act between array of pointers , matrix;
2. exploit performed overload of () operator indicated above , overloading = operator latter act between expression , matrix.

maybe first option not convenient, especilly large matrices. correct? there other more efficient/effective possibilities using perhaps more sophisticated c++ features (e.g., move semantics)?

thank help.

i think best bet have non-const version of operator()(range, range) return proxy object has overloaded assignment operator knows how assign range (back original matrix example).