From c1c8920024a6a6373f311dfdee3d78bc84bc9853 Mon Sep 17 00:00:00 2001
From: Daniel Wallin <daniel@boostpro.com>
Date: Wed, 15 Oct 2008 13:34:15 +0200
Subject: [PATCH] Add more API wrappers to object.hpp.

This adds tocfunction(), touserdata(), getupvalue(), setupvalue().
---
 doc/docs.rst         | 14 ++++++++++++++
 luabind/object.hpp   | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 test/test_object.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+)

diff --git a/doc/docs.rst b/doc/docs.rst
index f78509e..b674659 100755
--- a/doc/docs.rst
+++ b/doc/docs.rst
@@ -1249,6 +1249,20 @@ This function creates a new table and returns it as an object.
 
 These functions get and set the metatable of a Lua object.
 
+::
+
+  lua_CFunction tocfunction(object const& value);
+  template <class T> T* touserdata(object const& value)
+
+These extract values from the object at a lower level than ``object_cast()``.
+
+::
+
+  object getupvalue(object const& function, int index);
+  void setupvalue(object const& function, int index, object const& value);
+
+These get and set the upvalues of ``function``.
+
 Assigning nil
 -------------
 
diff --git a/luabind/object.hpp b/luabind/object.hpp
index 158855f..4b48d62 100644
--- a/luabind/object.hpp
+++ b/luabind/object.hpp
@@ -1251,6 +1251,57 @@ inline void setmetatable(
     lua_setmetatable(interpreter, -2);
 }
 
+template <class ValueWrapper>
+inline lua_CFunction tocfunction(ValueWrapper const& value)
+{
+    lua_State* interpreter = value_wrapper_traits<ValueWrapper>::interpreter(
+        value
+    );
+
+    value_wrapper_traits<ValueWrapper>::unwrap(interpreter, value);
+    detail::stack_pop pop(interpreter, 1);
+    return lua_tocfunction(interpreter, -1);
+}
+
+template <class T, class ValueWrapper>
+inline T* touserdata(ValueWrapper const& value)
+{
+    lua_State* interpreter = value_wrapper_traits<ValueWrapper>::interpreter(
+        value
+    );
+
+    value_wrapper_traits<ValueWrapper>::unwrap(interpreter, value);
+    detail::stack_pop pop(interpreter, 1);
+    return static_cast<T*>(lua_touserdata(interpreter, -1));
+}
+
+template <class ValueWrapper>
+inline object getupvalue(ValueWrapper const& value, int index)
+{
+    lua_State* interpreter = value_wrapper_traits<ValueWrapper>::interpreter(
+        value
+    );
+
+    value_wrapper_traits<ValueWrapper>::unwrap(interpreter, value);
+    detail::stack_pop pop(interpreter, 2);
+    lua_getupvalue(interpreter, -1, index);
+    return object(from_stack(interpreter, -1));
+}
+
+template <class ValueWrapper1, class ValueWrapper2>
+inline void setupvalue(
+    ValueWrapper1 const& function, int index, ValueWrapper2 const& value)
+{
+    lua_State* interpreter = value_wrapper_traits<ValueWrapper1>::interpreter(
+        function
+    );
+
+    value_wrapper_traits<ValueWrapper1>::unwrap(interpreter, function);
+    detail::stack_pop pop(interpreter, 1);
+    value_wrapper_traits<ValueWrapper2>::unwrap(interpreter, value);
+    lua_setupvalue(interpreter, -2, index);
+}
+
 } // namespace luabind
 
 #endif // LUABIND_OBJECT_050419_HPP
diff --git a/test/test_object.cpp b/test/test_object.cpp
index dd604fa..5063433 100644
--- a/test/test_object.cpp
+++ b/test/test_object.cpp
@@ -170,6 +170,46 @@ void test_metatable(lua_State* L)
 	assert(type(getmetatable(G["index_table"])["nonexistent"]) == LUA_TNIL);
 }
 
+int with_upvalues(lua_State *)
+{
+	return 0;
+}
+
+void test_upvalues(lua_State* L)
+{
+	lua_pushnumber(L, 3);
+	lua_pushnumber(L, 4);
+	lua_pushcclosure(L, &with_upvalues, 2);
+
+	object f(from_stack(L, -1));
+	lua_pop(L, 1);
+
+	assert(getupvalue(f, 1) == 3);
+	assert(getupvalue(f, 2) == 4);
+
+	setupvalue(f, 1, object(L, 4));
+	assert(getupvalue(f, 1) == 4);
+	assert(getupvalue(f, 2) == 4);
+
+	setupvalue(f, 2, object(L, 5));
+	assert(getupvalue(f, 1) == 4);
+	assert(getupvalue(f, 2) == 5);
+}
+
+void test_explicit_conversions(lua_State* L)
+{
+	lua_pushcclosure(L, &with_upvalues, 0);
+	object f(from_stack(L, -1));
+	lua_pop(L, 1);
+	assert(tocfunction(f) == &with_upvalues);
+
+	int* p = static_cast<int*>(lua_newuserdata(L, sizeof(int)));
+	*p = 1234;
+	object x(from_stack(L, -1));
+	lua_pop(L, 1);
+	assert(*touserdata<int>(x) == 1234);
+}
+
 void test_main(lua_State* L)
 {
 	using namespace luabind;
@@ -348,5 +388,7 @@ void test_main(lua_State* L)
 
     test_call(L);
     test_metatable(L);
+    test_upvalues(L);
+    test_explicit_conversions(L);
 }
 
-- 
2.11.4.GIT