From b5e3c8816dde8fea530906157ce3dcef05e5b026 Mon Sep 17 00:00:00 2001
From: Mike Bosse <mike.bosse@mavt.ethz.ch>
Date: Thu, 4 Dec 2014 22:15:20 +0100
Subject: [PATCH] added vector space concept check, but not sure it will
 work...

---
 gtsam/base/concepts.h | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/gtsam/base/concepts.h b/gtsam/base/concepts.h
index b231dfe0d..cc86d98ac 100644
--- a/gtsam/base/concepts.h
+++ b/gtsam/base/concepts.h
@@ -50,7 +50,6 @@ template<class T>
 class ManifoldConcept {
  public:
   typedef T Manifold;
-  typedef traits::manifold_tag<T> manifold_tag;
   typedef traits::TangentVector<T>::type TangentVector;
   typedef traits::DefaultChart<T>::type DefaultChart;
   static const size_t dim = traits::dimension<T>::value;
@@ -126,7 +125,29 @@ class LieGroupConcept : public GroupConcept<L>, public ManifoldConcept<L> {
   }
 };
 
+template <class V>
+class VectorSpaceConcept : public LieGroupConcept {
+  typedef traits::DefaultChart<V>::type Chart;
+  typedef GroupConcept<V>::identity identity;
 
+  BOOST_CONCEPT_USAGE(VectorSpaceConcept) {
+    BOOST_STATIC_ASSERT(boost::is_base_of<traits::vector_space_tag, traits::structure<L> >);
+    r = p+q;
+    r = -p;
+    r = p-q;
+  }
+
+  bool check_invariants(const V& a, const V& b) {
+    return equal(compose(a, b), a+b)
+        && equal(inverse(a), -a)
+        && equal(between(a, b), b-a)
+        && equal(Chart::retract(a, b), a+b)
+        && equal(Chart::local(a, b), b-a);
+  }
+
+ private:
+  V p,q,r;
+};
 
 } // namespace gtsam