Added overloads of sparse_matrix_vector_multiply() that return their result

like normal rather than passing it back by reference.

dlib/svm/sparse_vector.h

@@ -942,6 +942,19 @@ namespace dlib
         }
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <typename EXP>
+    matrix<typename EXP::type,0,1> sparse_matrix_vector_multiply (
+        const std::vector<sample_pair>& edges,
+        const matrix_exp<EXP>& v
+    )
+    {
+        matrix<typename EXP::type,0,1> result;
+        sparse_matrix_vector_multiply(edges,v,result);
+        return result;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <typename EXP, typename T, long NR, long NC, typename MM, typename L>
@@ -975,6 +988,19 @@ namespace dlib
         }
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <typename EXP>
+    matrix<typename EXP::type,0,1> sparse_matrix_vector_multiply (
+        const std::vector<ordered_sample_pair>& edges,
+        const matrix_exp<EXP>& v
+    )
+    {
+        matrix<typename EXP::type,0,1> result;
+        sparse_matrix_vector_multiply(edges,v,result);
+        return result;
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/svm/sparse_vector_abstract.h

@@ -576,6 +576,46 @@ namespace dlib
               (i.e. result will have the same dimensions as v)
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename EXP
+        >
+    matrix<typename EXP::type,0,1> sparse_matrix_vector_multiply (
+        const std::vector<sample_pair>& edges,
+        const matrix_exp<EXP>& v
+    );
+    /*!
+        requires
+            - is_col_vector(v) == true
+            - max_index_plus_one(edges) <= v.size()
+        ensures
+            - This is just a convenience routine for invoking the above
+              sparse_matrix_vector_multiply() routine.  In particular, it just calls
+              sparse_matrix_vector_multiply() with a temporary result matrix and then
+              returns the result.
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename EXP
+        >
+    matrix<typename EXP::type,0,1> sparse_matrix_vector_multiply (
+        const std::vector<ordered_sample_pair>& edges,
+        const matrix_exp<EXP>& v
+    );
+    /*!
+        requires
+            - is_col_vector(v) == true
+            - max_index_plus_one(edges) <= v.size()
+        ensures
+            - This is just a convenience routine for invoking the above
+              sparse_matrix_vector_multiply() routine.  In particular, it just calls
+              sparse_matrix_vector_multiply() with a temporary result matrix and then
+              returns the result.
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
 }