Don't need AudacityException::Move, use std::exception_ptr

src/AudacityApp.cpp

@@ -1083,7 +1083,7 @@ bool AudacityApp::OnExceptionInMainLoop()
       // Use CallAfter to delay this to the next pass of the event loop,
       // rather than risk doing it inside stack unwinding.
       auto pProject = ::GetActiveProject();
-      std::shared_ptr< AudacityException > pException { e.Move().release() };
+      auto pException = std::current_exception();
       CallAfter( [=]      // Capture pException by value!
       {
 
@@ -1097,7 +1097,9 @@ bool AudacityApp::OnExceptionInMainLoop()
          pProject->RedrawProject();
 
          // Give the user an alert
-         pException->DelayedHandlerAction();
+         try { std::rethrow_exception( pException ); }
+         catch( AudacityException &e )
+            { e.DelayedHandlerAction(); }
 
       } );
 

src/AudacityException.cpp

@@ -85,12 +85,6 @@ wxString SimpleMessageBoxException::ErrorMessage() const
    return message;
 }
 
-std::unique_ptr< AudacityException > SimpleMessageBoxException::Move()
-{
-   return std::unique_ptr< AudacityException >
-   { safenew SimpleMessageBoxException{ std::move( *this ) } };
-}
-
 // This is meant to be invoked via wxEvtHandler::CallAfter
 void MessageBoxException::DelayedHandlerAction()
 {

src/AudacityException.h

@@ -30,11 +30,6 @@ public:
    AudacityException() {}
    virtual ~AudacityException() = 0;
 
-   // This is intended as a "polymorphic move copy constructor"
-   // which leaves this "empty".
-   // We would not need this if we had std::exception_ptr
-   virtual std::unique_ptr< AudacityException > Move() = 0;
-
    // Action to do in the main thread at idle time of the event loop.
    virtual void DelayedHandlerAction() = 0;
 
@@ -88,8 +83,6 @@ public:
    SimpleMessageBoxException &operator = (
       SimpleMessageBoxException && ) PROHIBITED;
 
-   std::unique_ptr< AudacityException > Move() override;
-
    // Format a default, internationalized error message for this exception.
    virtual wxString ErrorMessage() const override;
 
@@ -170,11 +163,15 @@ R GuardedCall
    catch ( AudacityException &e ) {
 
       auto end = finally([&]{
+         // At this point, e is the "current" exception, but not "uncaught"
+         // unless it was rethrown by handler.  handler might also throw some
+         // other exception object.
          if (!std::uncaught_exception()) {
-            auto pException =
-               std::shared_ptr< AudacityException > { e.Move().release() };
+            auto pException = std::current_exception(); // This points to e
             wxTheApp->CallAfter( [=] { // capture pException by value
-               delayedHandler( pException.get() );
+               try { std::rethrow_exception(pException); }
+               catch( AudacityException &e )
+                  { delayedHandler( &e ); }
             } );
          }
       });

src/FileException.cpp

@@ -15,12 +15,6 @@ FileException::~FileException()
 {
 }
 
-std::unique_ptr< AudacityException > FileException::Move()
-{
-   return std::unique_ptr< AudacityException >
-      { safenew FileException{ std::move( *this ) } };
-}
-
 wxString FileException::ErrorMessage() const
 {
    wxString format;

src/FileException.h

@@ -37,8 +37,6 @@ public:
    ~FileException() override;
 
 protected:
-   std::unique_ptr< AudacityException > Move() override;
-
    // Format a default, internationalized error message for this exception.
    wxString ErrorMessage() const override;
 

src/InconsistencyException.cpp

@@ -14,12 +14,6 @@ InconsistencyException::~InconsistencyException()
 {
 }
 
-std::unique_ptr< AudacityException > InconsistencyException::Move()
-{
-   return std::unique_ptr< AudacityException >
-   { safenew InconsistencyException{ std::move( *this ) } };
-}
-
 wxString InconsistencyException::ErrorMessage() const
 {
    // Shorten the path

src/InconsistencyException.h

@@ -48,8 +48,6 @@ public:
    unsigned GetLine() const { return line; }
 
 private:
-   std::unique_ptr< AudacityException > Move() override;
-
    // Format a default, internationalized error message for this exception.
    wxString ErrorMessage() const override;
 

src/UserException.cpp

@@ -13,12 +13,6 @@ UserException::~UserException()
 {
 }
 
-std::unique_ptr< AudacityException > UserException::Move()
-{
-   return std::unique_ptr< AudacityException >
-   { safenew UserException{ std::move( *this ) } };
-}
-
 void UserException::DelayedHandlerAction()
 {
 }

src/UserException.h

@@ -30,9 +30,6 @@ public:
    ~UserException() override;
 
    void DelayedHandlerAction() override;
-
-private:
-   std::unique_ptr< AudacityException > Move() override;
 };
 
 #endif

src/blockfile/NotYetAvailableException.cpp

@@ -14,12 +14,6 @@ NotYetAvailableException::~NotYetAvailableException()
 {
 }
 
-std::unique_ptr< AudacityException > NotYetAvailableException::Move()
-{
-   return std::unique_ptr< AudacityException >
-   { safenew NotYetAvailableException{ std::move( *this ) } };
-}
-
 wxString NotYetAvailableException::ErrorMessage() const
 {
    return wxString::Format(

src/blockfile/NotYetAvailableException.h

@@ -25,7 +25,6 @@ public:
    ~NotYetAvailableException();
 
 protected:
-   std::unique_ptr< AudacityException > Move() override;
    wxString ErrorMessage() const override;
 };