Gave the sparse vector tools their own #include file.

dlib/sparse_vector.h

+// Copyright (C) 2012  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_SPaRSE_VECTOR_H__
+#define DLIB_SPaRSE_VECTOR_H__ 
+
+#include "svm/sparse_vector.h"
+
+#endif // DLIB_SPaRSE_VECTOR_H__ 
+
+

dlib/svm/sparse_vector.h

@@ -11,6 +11,7 @@
 #include <map>
 // This is included just so we can do some disable_if stuff on it in the max_index_plus_one routine().
 #include "../manifold_regularization/sample_pair.h"
+#include "../matrix.h"
 
 
 namespace dlib

dlib/svm/sparse_vector_abstract.h

@@ -6,6 +6,7 @@
 #include <cmath>
 #include "../algs.h"
 #include "../serialize.h"
+#include "../matrix.h"
 #include <map>
 #include <vector>
 

dlib/test/sparse_vector.cpp

 // Copyright (C) 2012  Davis E. King (davis@dlib.net)
 // License: Boost Software License   See LICENSE.txt for the full license.
 
+#include <dlib/sparse_vector.h>
 #include "tester.h"
-#include <dlib/svm.h>
 #include <dlib/rand.h>
 #include <dlib/string.h>
 #include <vector>