pyo3-benchmarks: add benchmark for class init

examples/pyo3-benchmarks/src/lib.rs

@@ -55,6 +55,17 @@ fn args_kwargs<'a>(
     (args, kwargs)
 }
 
+#[pyclass]
+struct EmptyClass {}
+
+#[pymethods]
+impl EmptyClass {
+    #[new]
+    fn new() -> Self {
+        EmptyClass {}
+    }
+}
+
 #[pymodule]
 fn _pyo3_benchmarks(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(none, m)?)?;
@@ -63,5 +74,6 @@ fn _pyo3_benchmarks(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(simple_kwargs, m)?)?;
     m.add_function(wrap_pyfunction!(simple_args_kwargs, m)?)?;
     m.add_function(wrap_pyfunction!(args_kwargs, m)?)?;
+    m.add_class::<EmptyClass>()?;
     Ok(())
 }

examples/pyo3-benchmarks/tests/test_benchmarks.py

@@ -89,3 +89,15 @@ def test_args_kwargs_rs(benchmark):
     py = args_kwargs_py(1, "foo", {1: 2}, bar=4, foo=10)
     assert rust == py
     benchmark(pyo3_benchmarks.args_kwargs, 1, "foo", {1: 2}, a=4, foo=10)
+
+
+def test_empty_class_init(benchmark):
+    benchmark(pyo3_benchmarks.EmptyClass)
+
+
+class EmptyClassPy:
+    pass
+
+
+def test_empty_class_init_py(benchmark):
+    benchmark(EmptyClassPy)