Correction to 9b89183bc0677 ?
#1295 Removed nz_indexed, nz_indexed_zero_based, nz_indexed_one_based overloads
#1295 Removed nz_indexed_one_based_assignment, nz_indexed_zero_based_assignment, nz_indexed_assignment
#1295 Fixed bug in indexed_zero_based.
The bug allows getting nonzeros using submatrix access syntax