From 613a6ff76307053f5dda4bb14c4474caad1a9b6f Mon Sep 17 00:00:00 2001
From: Ronan Abhamon <ronan.abhamon@belledonne-communications.com>
Date: Mon, 2 Oct 2017 10:14:43 +0200
Subject: [PATCH] feat(core): add a private-access file to access private data

---
 include/linphone/utils/private-access.h | 60 +++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 include/linphone/utils/private-access.h

diff --git a/include/linphone/utils/private-access.h b/include/linphone/utils/private-access.h
new file mode 100644
index 000000000..776fd8043
--- /dev/null
+++ b/include/linphone/utils/private-access.h
@@ -0,0 +1,60 @@
+/*
+ * private-access.h
+ * Copyright (C) 2017  Belledonne Communications SARL
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// =============================================================================
+// Tools to get/set private data of Cpp objects.
+//
+// See: https://bloglitb.blogspot.fr/2011/12/access-to-private-members-safer.html
+// See: http://en.cppreference.com/w/cpp/language/adl
+// See: http://en.cppreference.com/w/cpp/language/friend
+// =============================================================================
+
+#ifndef _PRIVATE_ACCESS_H_
+#define _PRIVATE_ACCESS_H_
+
+#include <type_traits>
+
+#define L_INTERNAL_STRUCT_L_ATTR_GET(CLASS, ATTR_NAME) AttrGet ## _ ## CLASS ## _ ## ATTR_NAME
+#define L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME) AttrSpy ## _ ## ATTR_NAME
+
+#define L_ENABLE_ATTR_ACCESS(CLASS, ATTR_TYPE, ATTR_NAME) \
+	template<typename AttrSpy, ATTR_TYPE CLASS::*Attr> \
+	struct L_INTERNAL_STRUCT_L_ATTR_GET(CLASS, ATTR_NAME) { \
+	friend constexpr ATTR_TYPE (CLASS::*get(AttrSpy *)) { \
+			return Attr; \
+		} \
+	}; \
+	template<typename T> \
+	struct L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME); \
+	template<> \
+	struct L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME)<CLASS> { \
+		friend constexpr ATTR_TYPE (CLASS::*get(L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME)<CLASS> *)); \
+	}; \
+	template struct L_INTERNAL_STRUCT_L_ATTR_GET(CLASS, ATTR_NAME)< \
+		L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME)<CLASS>, \
+		&CLASS::ATTR_NAME \
+	>;
+
+// Warning: Allow to modify const data.
+// Returns a ref to `ATTR_NAME`.
+#define L_ATTR_GET(OBJECT, ATTR_NAME) \
+	(const_cast<std::remove_const<decltype(OBJECT)>::type &>(OBJECT)).*get( \
+		static_cast<L_INTERNAL_STRUCT_ATTR_SPY(ATTR_NAME)<std::decay<decltype(OBJECT)>::type> *>(nullptr) \
+	)
+
+#endif // ifndef _PRIVATE_ACCESS_H_