c++ - shared_ptr : std::get_deleter does not work -

i have weird beahviour happening when trying deleter of shared pointer. here problematic bit of code:

shared_ptr<idecklinkvideoframe> videoframe = decklinkdevice_->getvideoframe(decklinkfourcc_); if(std::get_deleter<comobjectdeleter<idecklinkvideoframe>>(videoframe)) {     // never gets here } 

i never inside if because get_deleter() returns null. inside function getvideoframe() create shared_ptr deleter follow:

shared_ptr<idecklinkvideoframe> decklinkdevice::getvideoframe(fourcc framefourcc) { bmdpixelformat pixelformat = fourcctobmdpixelformat(framefourcc); shared_ptr<idecklinkvideoframe> frame; idecklinkmutablevideoframe* videoframe = null; long rowbytes = 0; bmdframeflags flags = 0; switch (pixelformat) { case bmdformat8bitbgra:     rowbytes = outputmode_->width_ * 4;     flags = bmdframeflagflipvertical;     break; case bmdformat8bityuv:     rowbytes = outputmode_->width_ * 2;     flags = bmdframeflagdefault;     break; default:     break; } if (rowbytes == 0) {     module_errorf("pixel format %1 not supprted") << pixelformat; } else if (createvideoframe(outputmode_->width_, outputmode_->height_, rowbytes, pixelformat, flags, &videoframe) != s_ok) {     module_errorf("failed obtain frame output."); } else {     frame.reset(videoframe, comobjectdeleter<idecklinkvideoframe>()); }  if(std::get_deleter<comobjectdeleter<idecklinkvideoframe>>(frame)) {     // here works can deleter } return frame; 

and if try call get_deleter() inside function works. looks deleter gets lost when function getvideoframe() returns... idea what's happenning , how can fix it?

thanks.