[Discuss-gnuradio] Using Out-of-Tree module from C++ Application

[Michael Buettner]

I am trying to use an out of tree module (built according to the
"Out-of-tree modules" documentation) from a C++ application. The
module is named "reader", and the block I'm trying to use is
"command_gate_cc".

I can use it from python with:
  from reader import reader_swig
  ...
  cg_block = reader_swig.command_gate_cc_make()

I can't figure out how to create a command_gate_cc block in C++ though.

/usr/local/lib/libgnuradio-reader.so exists, and 'nm -CD
/usr/local/lib/libgnuradio-reader.so' gives me
'0000000000004850 T gr::reader::command_gate_cc::make()'

/usr/include/reader_command_gate_cc.h exists:

namespace gr {
  namespace reader {

    class READER_API command_gate_cc : virtual public gr_block
    {
     public:
      typedef boost::shared_ptr<command_gate_cc> sptr;
      static sptr make();
    };

  } // namespace reader
} // namespace gr

My CC applications has:
#include <command_gate_cc.h>
...
boost::shared_ptr<gr::reader::command_gate_cc> cg =
gr::reader::command_gate_cc::make();

But I get the linker error:
undefined reference to `gr::reader::command_gate_cc::make()'

What am I missing? I don't understand the build system well enough to
figure out where if that is where I'm going wrong. Any help would be
appreciated. Thanks!