From defc9025718164bea696e06f6b9c82830dec4d79 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 5 Apr 2022 04:45:01 +0200
Subject: [PATCH] Allow to use Destructible as virtual base class

This is in preparation for a pure-virtual base class for
PluginInsert to expose `DropReferences` in the virtual base.

```
class PlugInsertBase : virtual public PBD::Destructible
class PluginInsert : public Processor, public PlugInsertBase
class Processor : public SessionObject
class SessionObject : public PBD::StatefulDestructible
```
---
 libs/pbd/pbd/destructible.h         | 3 +--
 libs/pbd/pbd/statefuldestructible.h | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/libs/pbd/pbd/destructible.h b/libs/pbd/pbd/destructible.h
index 8acbed05e2..804f32fedc 100644
--- a/libs/pbd/pbd/destructible.h
+++ b/libs/pbd/pbd/destructible.h
@@ -25,8 +25,7 @@
 namespace PBD {
 
 class LIBPBD_API Destructible {
-  public:
-        Destructible() {}
+public:
 	virtual ~Destructible () { Destroyed(); }
 
 	PBD::Signal0<void> Destroyed;
diff --git a/libs/pbd/pbd/statefuldestructible.h b/libs/pbd/pbd/statefuldestructible.h
index d2cf87db10..274457c88f 100644
--- a/libs/pbd/pbd/statefuldestructible.h
+++ b/libs/pbd/pbd/statefuldestructible.h
@@ -26,7 +26,7 @@
 namespace PBD {
 
 /** Base class for objects with saveable and undoable state with destruction notification */
-class LIBPBD_API StatefulDestructible : public Stateful, public Destructible
+class LIBPBD_API StatefulDestructible : public Stateful, virtual public Destructible
 {
 };