Added implicit conversions of std_vector_c back to std::vector so that

it can be used with functions that expect std::vector objects.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%402964

dlib/stl_checked/std_vector_c.h

@@ -50,6 +50,9 @@ namespace dlib
         std_vector_c(const std_vector_c<T,Allocator>& x) : impl(x.impl) {}
         std_vector_c(const std::vector<T,Allocator>& x) : impl(x) {}
 
+        operator const base_type& () const { return impl; }
+        operator base_type& () { return impl; }
+
         std_vector_c<T,Allocator>& operator=(const std_vector_c<T,Allocator>& x)
         {
             impl = x.impl;

dlib/stl_checked/std_vector_c_abstract.h

@@ -91,6 +91,22 @@ namespace dlib
                 - #*this == x
         !*/
 
+        operator const std::vector<T,Allocator>& (
+        ) const;
+        /*!
+            ensures
+                - returns a const reference to the normal unchecked std::vector
+                  object contained inside *this
+        !*/
+
+        operator std::vector<T,Allocator>& (
+        );
+        /*!
+            ensures
+                - returns a non-const reference to the normal unchecked std::vector
+                  object contained inside *this
+        !*/
+
         std_vector_c<T,Allocator>& operator= (
             const std_vector_c<T,Allocator>& x
         );