Hi Jan, first of, I recommend using the string macros icxx and cxx over the @cxx syntax. That should make it a lot clearer what's happening. To answer your question,
@cxx reader, is the equivalent of icxx"reader;", however @cxx reader->stuff is the equivalent of icxx"$reader->stuff", so reader is searched for in julia scope rather than C++ scope. Hope that makes sense. Keno On Wed, May 25, 2016 at 7:54 PM, Jan Strube <jan.str...@gmail.com> wrote: > I've created a rudimentary set of bindings to the LCIO file format > <http://lcio.desy.de/v02-07/doc/>. > It's an event data model and file format for detector and physics studies > of future linear collider concepts. > The code is over on github https://github.com/jstrube/LCIO.jl > The purpose of this post isn't to announce this code, however, since at > the moment it's rather fugly and jumping through extern "C" {} stubs. > > I would like to improve the usability a little and thought that Cxx.jl > could help with that, but I'm struggling with the first steps. > I have Cxx installed, but I'm confused about how to use it. > I'm using the following to set it up. > > using Cxx > addHeaderDir(joinpath(ENV["LCIO"], "include"), kind=C_User) > Libdl.dlopen(joinpath(ENV["LCIO"], "lib", "liblcio.so.2.7.1"), > Libdl.RTLD_GLOBAL) > cxxinclude("lcio.h") > cxxinclude("IO/LCReader.h") > cxxinclude("IOIMPL/LCFactory.h") > cxx"IO::LCReader* reader = > IOIMPL::LCFactory::getInstance()->createLCReader();" > > This works fine. > However, I would prefer this as the last line instead: > reader = @cxx IOIMPL::LCFactory::getInstance()->createLCReader() > > Unfortunately, this gives me "IOIMPL not defined." > Similarly, > julia> @cxx reader > (class IO::LCReader *) @0x0000000002fb0b70 > > julia> @cxx reader->open(pointer("gev250ee_higgs_ZZ_001_tracking.slcio")) > ERROR: UndefVarError: reader not defined > in eval(::Module, ::Any) at ./boot.jl:225 > in macro expansion at ./REPL.jl:92 [inlined] > in (::Base.REPL.##1#2{Base.REPL.REPLBackend})() at ./event.jl:46 > > So "reader" is found and has the right type, but when trying to access > member functions, it's no longer found??? > I'd file a bug report, but I'm not at all sure I'm actually using this > correctly. > > If you can think of a reason why this behavior is expected, and what I > could do to remedy, please let me know. > >
