diff --git a/dlib/matrix/matrix.h b/dlib/matrix/matrix.h
index 06e4240d2..d62007bca 100644
--- a/dlib/matrix/matrix.h
+++ b/dlib/matrix/matrix.h
@@ -895,17 +895,13 @@ namespace dlib
         >
     void matrix_assign (
         matrix_dest_type& dest,
-        const matrix_exp<src_exp>& src,
-        const long row_offset = 0,
-        const long col_offset = 0
+        const matrix_exp<src_exp>& src
     )
     /*!
         requires
             - src.destructively_aliases(dest) == false
-            - dest.nr() == src.nr()-row_offset
-            - dest.nc() == src.nc()-col_offset
         ensures
-            - #subm(dest, row_offset, col_offset, src.nr(), src.nc()) == src
+            - #dest == src
             - the part of dest outside the above sub matrix remains unchanged
     !*/
     {
@@ -913,7 +909,7 @@ namespace dlib
         {
             for (long c = 0; c < src.nc(); ++c)
             {
-                dest(r+row_offset,c+col_offset) = src(r,c);
+                dest(r,c) = src(r,c);
             }
         }
     }
diff --git a/dlib/matrix/matrix_assign.h b/dlib/matrix/matrix_assign.h
index 23bfb7b43..51b1858a6 100644
--- a/dlib/matrix/matrix_assign.h
+++ b/dlib/matrix/matrix_assign.h
@@ -56,9 +56,7 @@ namespace dlib
     inline typename disable_if_c<ma::matrix_is_vector<EXP1>::value || ma::matrix_is_vector<EXP2>::value ||
                                  ma::is_small_matrix<EXP1>::value || ma::is_small_matrix<EXP2>::value >::type matrix_assign (
         matrix_dest_type& dest,
-        const matrix_exp<matrix_multiply_exp<EXP1,EXP2,count> >& src,
-        const long row_offset = 0,
-        const long col_offset = 0
+        const matrix_exp<matrix_multiply_exp<EXP1,EXP2,count> >& src
     )
     /*!
         This overload catches assignments like:
@@ -78,7 +76,7 @@ namespace dlib
             {
                 for (long c = 0; c < src.nc(); ++c)
                 {
-                    dest(r+row_offset,c+col_offset) = src(r,c);
+                    dest(r,c) = src(r,c);
                 }
             }
         }
@@ -103,7 +101,6 @@ namespace dlib
 
                         // make a target rect in res
                         rectangle res_block(rhs_block.left(),lhs_block.top(), rhs_block.right(), lhs_block.bottom());
-                        res_block = translate_rect(res_block,col_offset, row_offset);
                         if (c != 0)
                             set_subm(dest, res_block) = subm(dest,res_block) + subm(lhs,lhs_block)*subm(rhs, rhs_block);
                         else
diff --git a/dlib/matrix/matrix_utilities.h b/dlib/matrix/matrix_utilities.h
index 1ce268c7a..56e54a34b 100644
--- a/dlib/matrix/matrix_utilities.h
+++ b/dlib/matrix/matrix_utilities.h
@@ -2304,6 +2304,17 @@ convergence:
             const rectangle& rect_
         ) : m(m_), rect(rect_) {}
 
+        T& operator() (
+            long r,
+            long c
+        )
+        {
+            return m(r+rect.top(),c+rect.left());
+        }
+
+        long nr() const { return rect.height(); }
+        long nc() const { return rect.width(); }
+
         template <typename EXP>
         assignable_sub_matrix& operator= (
             const matrix_exp<EXP>& exp
@@ -2320,7 +2331,7 @@ convergence:
 
             if (exp.destructively_aliases(m) == false)
             {
-                matrix_assign(m, exp, rect.top(), rect.left()); 
+                matrix_assign(*this, exp); 
             }
             else
             {
@@ -2411,6 +2422,18 @@ convergence:
             const EXPc& cols_
         ) : m(m_), rows(rows_), cols(cols_) {}
 
+        T& operator() (
+            long r,
+            long c
+        )
+        {
+            return m(rows(r),cols(c));
+        }
+
+        long nr() const { return rows.size(); }
+        long nc() const { return cols.size(); }
+
+
         template <typename EXP>
         assignable_sub_range_matrix& operator= (
             const matrix_exp<EXP>& exp
@@ -2427,13 +2450,7 @@ convergence:
 
             if (exp.destructively_aliases(m) == false)
             {
-                for (long r = 0; r < rows.size(); ++r)
-                {
-                    for (long c = 0; c < cols.size(); ++c)
-                    {
-                        m(rows(r),cols(c)) = exp(r,c);
-                    }
-                }
+                matrix_assign(*this, exp);
             }
             else
             {
@@ -2504,6 +2521,17 @@ convergence:
             const long col_ 
         ) : m(m_), col(col_) {}
 
+        T& operator() (
+            long r,
+            long c
+        )
+        {
+            return m(r,col);
+        }
+
+        long nr() const { return m.nr(); }
+        long nc() const { return 1; }
+
         template <typename EXP>
         assignable_col_matrix& operator= (
             const matrix_exp<EXP>& exp
@@ -2519,7 +2547,7 @@ convergence:
 
             if (exp.destructively_aliases(m) == false)
             {
-                matrix_assign(m, exp, 0, col); 
+                matrix_assign(*this, exp); 
             }
             else
             {
@@ -2580,6 +2608,19 @@ convergence:
             const long row_ 
         ) : m(m_), row(row_) {}
 
+
+        T& operator() (
+            long r,
+            long c
+        )
+        {
+            return m(row,c);
+        }
+
+        long nr() const { return 1; }
+        long nc() const { return m.nc(); }
+
+
         template <typename EXP>
         assignable_row_matrix& operator= (
             const matrix_exp<EXP>& exp
@@ -2595,7 +2636,7 @@ convergence:
 
             if (exp.destructively_aliases(m) == false)
             {
-                matrix_assign(m, exp, row, 0); 
+                matrix_assign(*this, exp); 
             }
             else
             {