From e12b123cf0daab6858fd29fd56e10f1c6850249d Mon Sep 17 00:00:00 2001
From: Ronan Abhamon <ronan.abhamon@belledonne-communications.com>
Date: Fri, 13 Oct 2017 11:08:49 +0200
Subject: [PATCH] feat(General): provide a way to get private data in a a
 multiple inheritance case.

---
 include/linphone/utils/general.h              | 30 +++++++++++++++++--
 src/chat/chat-room/client-group-chat-room.cpp |  4 +--
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/include/linphone/utils/general.h b/include/linphone/utils/general.h
index 8e9e5d146..1ccee3b72 100644
--- a/include/linphone/utils/general.h
+++ b/include/linphone/utils/general.h
@@ -20,6 +20,10 @@
 #ifndef _GENERAL_H_
 #define _GENERAL_H_
 
+#ifdef __cplusplus
+	#include <type_traits>
+#endif
+
 // =============================================================================
 
 #ifdef __cplusplus
@@ -151,8 +155,30 @@ constexpr T *getPublicHelper (Object *object, const ObjectPrivate *) {
 	CLASS (const CLASS &) = delete; \
 	CLASS &operator= (const CLASS &) = delete;
 
-#define L_D() decltype(std::declval<decltype(*this)>().getPrivate()) const d = getPrivate();
-#define L_Q() decltype(std::declval<decltype(*this)>().getPublic()) const q = getPublic();
+// Get Private data.
+#define L_D() decltype(getPrivate()) const d = getPrivate();
+
+// Get Public data.
+#define L_Q() decltype(getPublic()) const q = getPublic();
+
+template<typename T, typename U>
+struct AddConstMirror {
+	typedef U type;
+};
+
+template<typename T, typename U>
+struct AddConstMirror<const T, U> {
+	typedef typename std::add_const<U>::type type;
+};
+
+// Get Private data of class in a multiple inheritance case.
+#define L_D_T(CLASS, NAME) \
+	auto const NAME = static_cast< \
+		AddConstMirror< \
+			std::remove_reference<decltype(*this)>::type, \
+			CLASS ## Private \
+		>::type * \
+	>(CLASS::mPrivate);
 
 #define L_OVERRIDE_SHARED_FROM_THIS(CLASS) \
 	inline std::shared_ptr<CLASS> getSharedFromThis () { \
diff --git a/src/chat/chat-room/client-group-chat-room.cpp b/src/chat/chat-room/client-group-chat-room.cpp
index 3fdc1bb74..9d0e85137 100644
--- a/src/chat/chat-room/client-group-chat-room.cpp
+++ b/src/chat/chat-room/client-group-chat-room.cpp
@@ -211,6 +211,7 @@ void ClientGroupChatRoom::setParticipantAdminStatus (shared_ptr<Participant> &pa
 
 void ClientGroupChatRoom::setSubject (const string &subject) {
 	L_D();
+	L_D_T(RemoteConference, dConference);
 
 	if (d->state != ChatRoom::State::Created) {
 		lError() << "Cannot change the ClientGroupChatRoom subject in a state other than Created";
@@ -222,8 +223,7 @@ void ClientGroupChatRoom::setSubject (const string &subject) {
 		return;
 	}
 
-	shared_ptr<CallSession> session =
-		static_cast<RemoteConferencePrivate *>(Conference::mPrivate)->focus->getPrivate()->getSession();
+	shared_ptr<CallSession> session = dConference->focus->getPrivate()->getSession();
 	if (session)
 		session->update(nullptr, subject);
 	else {