I want to assign a matrix to submatrix of a bigger matrix.

Code:
ublas::matrix<int> A(8,5);
ublas::matrix<int> B(2,5);
for(size_t i=0;i<A.size1();++i)
    for(size_t j=0;j<A.size2();++j)
        A(i,j)=i*A.size2()+j+1;
for(size_t i=0;i<B.size1();++i)
    for(size_t j=0;j<B.size2();++j)
        B(i,j)=i*B.size2()+j+5;
ublas::matrix_range<ublas::matrix<int>
...