Marcus is right, but your approach should technically work as well. I rarely get C++ polymorphisms and pointers right at first go, but using dynamic_pointer_cast should work and be safe - ish.
M On 29 Jan 2016 10:28, "Marcus Müller" <marcus.muel...@ettus.com> wrote: > Sorry, I just got a friendly reminder that this is a bad idea in many > ways; the recommended way of getting a handle to your USRP block is passing > the block alias around and looking it up in the block registry; that's why > we have it anyway. > Make sure the result of the lookup is valid! > > Best regards, > Marcus > > Am 29. Januar 2016 09:13:42 MEZ, schrieb "Marcus Müller" < > marcus.muel...@ettus.com>: >> >> Hi Sean, >> >> it's been a while since I did that, but I think that "smart_ptr<A> cannot >> be casted to smart_ptr<B>" can be remedied using Boost's pointer_cast[1]. >> >> Hope that gives you a start. >> >> Best regards, >> Marcus >> >> [1] http://www.boost.org/doc/libs/1_60_0/libs/smart_ptr/pointer_cast.html >> On 01/28/2016 08:34 PM, Nowlan, Sean wrote: >> >> I have a USRP with a GPSDO. I am working on a block that will poll a USRP >> for PPS changes in an attempt to adjust for clock offset between host and >> USRP. Assume I have explicitly set the USRP time-of-day correctly to UTC >> using PPS and a set_time_next_pps_call, and GPS is locked. >> >> >> >> I would like to pass a USRP sink (or source) shared pointer to this >> block. It will have its own internal thread that will loop waiting for PPS >> edge transitions, polling with get_time_now, and then measuring offset >> between PC/system clock and USRP clock. >> >> >> >> Following guidance from a mailing list thread [1], I attempted to pass a >> usrp_sink shared pointer as a basic_block_sptr and then dynamic_cast it in >> the block xtor. Here’s the error I get: >> >> >> >> clock_manager_impl.cc: In constructor >> ‘gr::mymodule::clock_manager_impl::clock_manager_impl(gr::basic_block_sptr, >> double, const string&)’: >> >> clock_manager_impl.cc:50:59: error: cannot dynamic_cast ‘usrp’ (of type >> ‘gr::basic_block_sptr {aka class boost::shared_ptr<gr::basic_block>}’) to >> type ‘gr::uhd::usrp_sink::sptr {aka class >> boost::shared_ptr<gr::uhd::usrp_sink>}’ (target is not pointer or reference) >> >> d_usrp(dynamic_cast<gr::uhd::usrp_sink::sptr>(usrp)), >> >> >> >> Any advice on the best way to do this? Is my approach sane? >> >> >> >> Thanks, >> >> Sean >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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