core: add helpers to check Tensor support at run-time

include/eigenpy/eigenpy.hpp

@@ -19,6 +19,8 @@ namespace eigenpy {
  */
 void EIGENPY_DLLAPI enableEigenPy();
 
+bool EIGENPY_DLLAPI withTensorSupport();
+
 /* Enable the Eigen--Numpy serialization for the templated MatType class.*/
 template <typename MatType>
 void enableEigenPySpecific();

src/eigenpy.cpp

@@ -60,4 +60,12 @@ void enableEigenPy() {
   exposeNoneType();
 }
 
+bool withTensorSupport() {
+#ifdef EIGENPY_WITH_TENSOR_SUPPORT
+  return true;
+#else
+  return false;
+#endif
+}
+
 }  // namespace eigenpy