core: add regression tests

unittest/std_vector.cpp

@@ -30,6 +30,10 @@ void setZero(std::vector<MatType, Eigen::aligned_allocator<MatType> > &Ms) {
   }
 }
 
+struct CustomTestStruct {
+  bool operator==(const CustomTestStruct &) const { return true; }
+};
+
 BOOST_PYTHON_MODULE(std_vector) {
   namespace bp = boost::python;
   using namespace eigenpy;
@@ -58,4 +62,10 @@ BOOST_PYTHON_MODULE(std_vector) {
       .def(boost::python::vector_indexing_suite<
            std::vector<Eigen::Matrix2d> >());
   exposeStdVectorEigenSpecificType<Eigen::Matrix2d>("Mat2d");
+
+  // Test API regression:
+  // Exposing a `std::vector` with documentation doesn't clash with
+  // exposing a `std::vector` with a visitor
+  StdVectorPythonVisitor<std::vector<CustomTestStruct> >::expose(
+      "StdVec_CustomTestStruct", "some documentation");
 }