From 0991e90375606254087f7bffe0dd15dd910ec62b Mon Sep 17 00:00:00 2001
From: Wenzel Jakob <wenzel.jakob@epfl.ch>
Date: Sun, 11 Nov 2018 17:24:32 +0100
Subject: [PATCH] fix py::cast<void *>

Pybind11 provides a cast operator between opaque void* pointers on the
C++ side and capsules on the Python side. The py::cast<void *>
expression was not aware of this possibility and incorrectly triggered a
compile-time assertion ("Unable to cast type to reference: value is
local to type caster") that is now fixed.
---
 include/pybind11/cast.h        | 3 ++-
 tests/test_builtin_casters.cpp | 7 +++++++
 tests/test_builtin_casters.py  | 4 ++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index 2dec23cb3..80abb2b93 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -1611,7 +1611,8 @@ template <typename T> using move_never = none_of<move_always<T>, move_if_unrefer
 // everything else returns a reference/pointer to a local variable.
 template <typename type> using cast_is_temporary_value_reference = bool_constant<
     (std::is_reference<type>::value || std::is_pointer<type>::value) &&
-    !std::is_base_of<type_caster_generic, make_caster<type>>::value
+    !std::is_base_of<type_caster_generic, make_caster<type>>::value &&
+    !std::is_same<intrinsic_t<type>, void>::value
 >;
 
 // When a value returned from a C++ function is being cast back to Python, we almost always want to
diff --git a/tests/test_builtin_casters.cpp b/tests/test_builtin_casters.cpp
index 450813403..e026127f8 100644
--- a/tests/test_builtin_casters.cpp
+++ b/tests/test_builtin_casters.cpp
@@ -160,4 +160,11 @@ TEST_SUBMODULE(builtin_casters, m) {
     m.def("int_cast", []() {return (int) 42;});
     m.def("long_cast", []() {return (long) 42;});
     m.def("longlong_cast", []() {return  ULLONG_MAX;});
+
+    /// test void* cast operator
+    m.def("test_void_caster", []() -> bool {
+        void *v = (void *) 0xabcd;
+        py::object o = py::cast(v);
+        return py::cast<void *>(o) == v;
+    });
 }
diff --git a/tests/test_builtin_casters.py b/tests/test_builtin_casters.py
index 01d0437b5..73cc465f5 100644
--- a/tests/test_builtin_casters.py
+++ b/tests/test_builtin_casters.py
@@ -336,3 +336,7 @@ def test_int_long():
     assert isinstance(m.int_cast(), int)
     assert isinstance(m.long_cast(), int)
     assert isinstance(m.longlong_cast(), must_be_long)
+
+
+def test_void_caster_2():
+    assert m.test_void_caster()