Fixed some bugs and cleaned up the code.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402773

dlib/matrix/matrix_assign.h

@@ -237,9 +237,10 @@ namespace dlib
                 {
                     if (add_to)
                     {
-                        matrix<T,NR,NC,MM,L> temp(dest);
+                        matrix<T,NR,NC,MM,L> temp(dest.nr(),dest.nc());
+                        set_all_elements(temp,0);
                         default_matrix_multiply(temp, src.lhs, src.rhs);
-                        dest = alpha*temp;
+                        dest += alpha*temp;
                     }
                     else
                     {
@@ -288,6 +289,8 @@ namespace dlib
         /*!
             requires
                 - src.aliases(dest) == false
+                - dest.nr() == src.nr()
+                - dest.nc() == src.nc()
         !*/
 
         template <
@@ -303,6 +306,8 @@ namespace dlib
         /*!
             requires
                 - src.aliases(dest) == false
+                - dest.nr() == src.nr()
+                - dest.nc() == src.nc()
         !*/
 
         template <
@@ -318,6 +323,8 @@ namespace dlib
         /*!
             requires
                 - src.aliases(dest) == false
+                - dest.nr() == src.nr()
+                - dest.nc() == src.nc()
         !*/
 
         template <
@@ -333,6 +340,8 @@ namespace dlib
         /*!
             requires
                 - src.aliases(dest) == false
+                - dest.nr() == src.nr()
+                - dest.nc() == src.nc()
         !*/
 
     // ------------------------------------------------------------------------------------
@@ -481,7 +490,7 @@ namespace dlib
         {
             if (src.aliases(dest))
             {
-                matrix<T,NR,NC,MM,L> temp;
+                matrix<T,NR,NC,MM,L> temp(dest.nr(),dest.nc());
                 matrix_assign_blas_proxy(temp,src,1,false);
                 temp.swap(dest);
             }
@@ -526,6 +535,24 @@ namespace dlib
             }
         }
 
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T, long NR, long NC, typename MM, typename L,
+            typename src_exp 
+            >
+        void matrix_assign_blas (
+            matrix<T,NR,NC,MM,L>& dest,
+            const matrix_add_exp<src_exp, matrix<T,NR,NC,MM,L> >& src
+        )
+        {
+            // Just switch around the left and right hand sides of the incoming 
+            // add expression and pass it back into matrix_assign_blas() so that
+            // the above function will be called.
+            typedef matrix_add_exp<matrix<T,NR,NC,MM,L> ,src_exp> swapped_add_exp;
+            matrix_assign_blas(dest, swapped_add_exp(src.rhs, src.lhs)); 
+        }
+            
     // ------------------------------------------------------------------------------------
 
         template <

dlib/matrix/matrix_assign_fwd.h

@@ -47,6 +47,8 @@ namespace dlib
     /*!
         requires
             - src.destructively_aliases(dest) == false
+            - dest.nr() == src.nr()
+            - dest.nc() == src.nc()
         ensures
             - #dest == src
     !*/
@@ -72,6 +74,8 @@ namespace dlib
     /*!
         requires
             - src.destructively_aliases(dest) == false
+            - dest.nr() == src.nr()
+            - dest.nc() == src.nc()
         ensures
             - if (add_to == false) then
                 - #dest == alpha*src
@@ -164,6 +168,8 @@ namespace dlib
     /*!
         requires
             - src.destructively_aliases(dest) == false
+            - dest.nr() == src.nr()
+            - dest.nc() == src.nc()
         ensures
             - #dest == src
     !*/
@@ -187,6 +193,8 @@ namespace dlib
     /*!
         requires
             - src.destructively_aliases(dest) == false
+            - dest.nr() == src.nr()
+            - dest.nc() == src.nc()
         ensures
             - #dest == src
     !*/