Made it so you can pass a dlib::matrix to the array_to_matrix

and vector_to_matrix functions.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402374

dlib/matrix/matrix_utilities.h

@@ -1382,7 +1382,21 @@ namespace dlib
     template <
         typename array_type
         >
-    const matrix_exp<matrix_array_exp<array_type> > array_to_matrix (
+    const typename enable_if<is_matrix<array_type>,array_type>::type& 
+    array_to_matrix (
+        const array_type& array
+    )
+    {
+        return array;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename array_type
+        >
+    const typename disable_if<is_matrix<array_type>,matrix_exp<matrix_array_exp<array_type> > >::type 
+    array_to_matrix (
         const array_type& array
     )
     {
@@ -1395,7 +1409,8 @@ namespace dlib
     template <
         typename vector_type
         >
-    const matrix_exp<matrix_vector_exp<vector_type> > vector_to_matrix (
+    const typename disable_if<is_matrix<vector_type>,matrix_exp<matrix_vector_exp<vector_type> > >::type 
+    vector_to_matrix (
         const vector_type& vector
     )
     {
@@ -1403,6 +1418,18 @@ namespace dlib
         return matrix_exp<exp>(exp(vector));
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename vector_type
+        >
+    const typename enable_if<is_matrix<vector_type>,vector_type>::type& vector_to_matrix (
+        const vector_type& vector
+    )
+    {
+        return vector;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <

dlib/matrix/matrix_utilities_abstract.h

@@ -152,8 +152,11 @@ namespace dlib
     /*!
         requires
             - vector_type is an implementation of array/array_kernel_abstract.h or
-              std::vector or dlib::std_vector_c
+              std::vector or dlib::std_vector_c or dlib::matrix
         ensures
+            - if (vector_type is a dlib::matrix) then
+                - returns a reference to vector
+            - else
                 - returns a matrix R such that:
                     - R.nr() == vector.size() 
                     - R.nc() == 1 
@@ -172,7 +175,11 @@ namespace dlib
     /*!
         requires
             - array_type is an implementation of array2d/array2d_kernel_abstract.h
+              or dlib::matrix
         ensures
+            - if (array_type is a dlib::matrix) then
+                - returns a reference to array 
+            - else
                 - returns a matrix R such that:
                     - R.nr() == array.nr() 
                     - R.nc() == array.nc()