joints: add equal operator to specifi Transform types

src/multibody/joint/joint-prismatic.hpp

@@ -235,6 +235,11 @@ namespace pinocchio
     
     ConstLinearRef translation() const { return CartesianAxis3()*displacement(); };
     AngularType rotation() const { return AngularType(3,3); }
+    
+    bool isEqual(const TransformPrismaticTpl & other) const
+    {
+      return m_displacement == other.m_displacement;
+    }
 
   protected:
     

src/multibody/joint/joint-revolute.hpp

@@ -159,6 +159,11 @@ namespace pinocchio
       return m;
     }
     
+    bool isEqual(const TransformRevoluteTpl & other) const
+    {
+      return m_cos == other.m_cos && m_sin == other.m_sin;
+    }
+    
   protected:
     
     Scalar m_sin, m_cos;

src/multibody/joint/joint-translation.hpp

@@ -233,6 +233,11 @@ namespace pinocchio
     
     AngularType rotation() const { return AngularType(3,3); }
     
+    bool isEqual(const TransformTranslationTpl & other) const
+    {
+      return m_translation == other.m_translation;
+    }
+    
   protected:
     
     LinearType m_translation;