Added more asserts and a version number to the serialization

format for sequence_segmenter objects.

dlib/svm/sequence_segmenter.h

@@ -188,6 +188,14 @@ namespace dlib
 
         sequence_segmenter()
         {
+            const feature_extractor& fe = labeler.get_feature_extractor().fe;
+            DLIB_ASSERT(fe.window_size() >= 1 && fe.num_features() >= 1,
+                "\t sequence_segmenter::sequence_segmenter()"
+                << "\n\t An invalid feature extractor was supplied."
+                << "\n\t fe.window_size():  " << fe.window_size() 
+                << "\n\t fe.num_features(): " << fe.num_features() 
+                << "\n\t this: " << this
+            );
         }
 
         explicit sequence_segmenter(
@@ -204,6 +212,13 @@ namespace dlib
                 << "\n\t weights.size(): " << weights.size() 
                 << "\n\t this: " << this
                 );
+            DLIB_ASSERT(fe.window_size() >= 1 && fe.num_features() >= 1,
+                "\t sequence_segmenter::sequence_segmenter()"
+                << "\n\t An invalid feature extractor was supplied."
+                << "\n\t fe.window_size():  " << fe.window_size() 
+                << "\n\t fe.num_features(): " << fe.num_features() 
+                << "\n\t this: " << this
+            );
         }
 
         sequence_segmenter(
@@ -264,11 +279,17 @@ namespace dlib
 
         friend void serialize(const sequence_segmenter& item, std::ostream& out)
         {
+            int version = 1;
+            serialize(version, out);
             serialize(item.labeler, out);
         }
 
         friend void deserialize(sequence_segmenter& item, std::istream& in)
         {
+            int version = 0;
+            deserialize(version, in);
+            if (version != 1)
+                throw serialization_error("Unexpected version found while deserializing dlib::sequence_segmenter.");
             deserialize(item.labeler, in);
         }