Add ImplPtr and makeImpl

The original (more complex and comprehensive) solution belongs to
https://oliora.github.io/2015/12/29/pimpl-and-rule-of-zero.html - this
commit only provides a small wrapper for non-copyable Private class
implementations common throughout libQuotient. Unlike the original,
default initialisation is made explicit - you have to pass
ZeroImpl<Private>() instead (and I firmly believe it's a good thing:
normally pointers to Private should not remain nullptr). The reason
ZeroImpl<> is not a template variable is quite simple: unique_ptr is
non-copyable and so cannot be initialised from; while a template
function will initialise the value in-place thanks to copy elision.

1 files changed, 2 insertions, 4 deletions

diff --git a/lib/mxcreply.h b/lib/mxcreply.h
index 1d31d608..f6c4a34d 100644
--- a/lib/mxcreply.h
+++ b/lib/mxcreply.h
@@ -3,10 +3,9 @@
 
 #pragma once
 
-#include "quotient_export.h"
+#include "util.h"
 
 #include <QtNetwork/QNetworkReply>
-#include <memory>
 
 namespace Quotient {
 class Room;
@@ -18,7 +17,6 @@ public:
     explicit MxcReply();
     explicit MxcReply(QNetworkReply *reply);
     MxcReply(QNetworkReply* reply, Room* room, const QString& eventId);
-    ~MxcReply() override;
 
 public Q_SLOTS:
     void abort() override;
@@ -28,6 +26,6 @@ protected:
 
 private:
     class Private;
-    std::unique_ptr<Private> d;
+    ImplPtr<Private> d;
 };
 }