Fix application of keep_alive policy to constructors (regression)
diff --git a/docs/advanced/functions.rst b/docs/advanced/functions.rst
index cdf318c..c7892b5 100644
--- a/docs/advanced/functions.rst
+++ b/docs/advanced/functions.rst
@@ -191,6 +191,17 @@
py::class_<List>(m, "List")
.def("append", &List::append, py::keep_alive<1, 2>());
+For consistency, the argument indexing is identical for constructors. Index
+``1`` still refers to the implicit ``this`` pointer, i.e. the object which is
+being constructed. Index ``0`` refers to the return type which is presumed to
+be ``void`` when a constructor is viewed like a function. The following example
+ties the lifetime of the constructor element to the constructed object:
+
+.. code-block:: cpp
+
+ py::class_<Nurse>(m, "Nurse")
+ .def(py::init<Patient &>(), py::keep_alive<1, 2>());
+
.. note::
``keep_alive`` is analogous to the ``with_custodian_and_ward`` (if Nurse,