Fix for swig=>4.4.0

example/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
   "scikit-build-core",
-  "swig<4.4.0",
+  "swig",
   "pybind11",
   ]
 # Use a custom in-tree backend to inject local dependencies.

include/swigbind11/swigbind11.hpp

@@ -35,9 +35,13 @@ inline auto extract_swig_object(py::handle obj, std::string_view type_name) {
 
   // obj is a proxy object generated by SWIG, we need to extract the underlying SWIG object
   auto swig_obj = obj.attr("this");
-  const auto type = py::str(py::type::of(swig_obj)).cast<std::string>();
-  if (type != "<class 'SwigPyObject'>") {
-    throw py::cast_error{"expected SWIG-wrapped object, got: " + type};
+  const std::string type_str = py::str(py::type::of(swig_obj)).cast<std::string>();
+
+  // look for "SwigPyObject" in name
+  // type_str = <class 'SwigPyObject'>                        (SWIG <  4.4.0)
+  // type_str = <class 'swig_runtime_data5.SwigPyObject'>     (SWIG >= 4.4.0)
+  if (type_str.find("SwigPyObject") == std::string::npos) {
+    throw py::cast_error{"expected SWIG-wrapped object, got: " + type_str};
   }
 
   return swig_obj;

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
 requires = ["scikit-build-core",
-  "swig<4.4.0",
+  "swig",
   "setuptools-scm"
 ]
 build-backend = "scikit_build_core.build"