[libcamera-devel] [PATCH] libcamera: pipeline: fix c++20 compile warning

[Barnabás Pőcze]

Hi


2023. november 14., kedd 14:42 keltezéssel, Laurent Pinchart via libcamera-devel <libcamera-devel at lists.libcamera.org> írta:

> On Tue, Nov 14, 2023 at 12:53:04PM +0200, Laurent Pinchart via libcamera-devel wrote:
> 
> > Hi Brett,
> > 
> > Thank you for your first libcamera patch :-)
> > 
> > On Mon, Nov 13, 2023 at 09:52:44AM -0700, Brett Brotherton via libcamera-devel wrote:
> > 
> > > fix -Wdeprecated-this-capture error when building with c++20 by
> > > explicity naming this in the capture
> > 
> > Nitpicking, s/fix/Fix/ and s/capture$/capture./
> > 
> > No need to resend the patch for this, I'll update the commit message
> > before pushing.
> > 
> > Is this the only occurrence of implicit *this capture ? I'm happy we're
> > not doing that bad :-)
> > 
> > > Signed-off-by: Brett Brotherton bbrotherton at google.com
> > 
> > Reviewed-by: Laurent Pinchart laurent.pinchart at ideasonboard.com
> > 
> > I will run this through build testing and push the patch if no issues
> > are found.
> 
> 
> Unfortunately problems have been found :-(
> 
> ../../src/libcamera/pipeline_handler.cpp:652:40: error: explicit capture of 'this' with a capture default of '=' is a C++20 extension [-Werror,-Wc++20-extensions]
> media->disconnected.connect(this, =, this { mediaDeviceDisconnected(media); });
> 
> ^
> 

I imagine explicitly capturing everything needed should fix that.


diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 9c74c6cf..29e0c98a 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -649,7 +649,7 @@ void PipelineHandler::registerCamera(std::shared_ptr<Camera> camera)
  */
 void PipelineHandler::hotplugMediaDevice(MediaDevice *media)
 {
-       media->disconnected.connect(this, [=]() { mediaDeviceDisconnected(media); });
+       media->disconnected.connect(this, [this, media] { mediaDeviceDisconnected(media); });
 }
 
 /**



> > > ---
> > > src/libcamera/pipeline_handler.cpp | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> > > index 9c74c6cf..2220cb92 100644
> > > --- a/src/libcamera/pipeline_handler.cpp
> > > +++ b/src/libcamera/pipeline_handler.cpp
> > > @@ -649,7 +649,7 @@ void PipelineHandler::registerCamera(std::shared_ptr<Camera> camera)
> > > */
> > > void PipelineHandler::hotplugMediaDevice(MediaDevice *media)
> > > {
> > > - media->disconnected.connect(this, = { mediaDeviceDisconnected(media); });
> > > + media->disconnected.connect(this, =, this { mediaDeviceDisconnected(media); });
> > > }
> [...]


Regards,
Barnabás Pőcze