From ab26259c87152f676f66d2ae0e3ae7bcafa47fe2 Mon Sep 17 00:00:00 2001
From: Wenzel Jakob <wenzel.jakob@epfl.ch>
Date: Wed, 22 Mar 2017 21:39:19 +0100
Subject: [PATCH] added note about trailing commas (fixes #593)

---
 docs/advanced/classes.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/docs/advanced/classes.rst b/docs/advanced/classes.rst
index 232d13d59..8896441b6 100644
--- a/docs/advanced/classes.rst
+++ b/docs/advanced/classes.rst
@@ -230,6 +230,13 @@ override the ``name()`` method):
         std::string bark() override { PYBIND11_OVERLOAD(std::string, Dog, bark, ); }
     };
 
+.. note::
+
+    Note the trailing commas in the ``PYBIND11_OVERLOAD`` calls to ``name()``
+    and ``bark()``. These are needed to portably implement a trampoline for a
+    function that does not take any arguments. For functions that take
+    a nonzero number of arguments, the trailing comma must be omitted.
+
 A registered class derived from a pybind11-registered class with virtual
 methods requires a similar trampoline class, *even if* it doesn't explicitly
 declare or override any virtual methods itself: