Best way to deal with namespaces on cgo

[Alonso Vidales]

Hello,

I’m working on a project that makes usage of some C++ libraries, this libraries use namespaces like:

namespace ns {

void hello();

}

All compiles, and I can use the functions out of namespaces, but I can’t find docu about how to work with namespaces in order to access to this method from Go.

My first idea was to use a small wrapper using the cgo comments like:

package stuff

// #import <some_libs.h>

/*

void hello() {

ns::hello();

}

*/

import “C”

But this fails with an:

error: expected expression before ‘:'

another option is to prepare the wrapper out of the .go file, but this is going to make a bit more complicated the installation, etc of the libraries.

What is the best approach?, can I just call to this method using the C lib? something like: C.ns.hello()??

Thanks!,

[Ian Lance Taylor]

At present cgo only understands C, not C++. You need to use extern
"C" and give C names to the functions outside of cgo. For example,
put a export.cc file in your Go package directory that has extern "C"
wrappers. Then you can refer to those wrappers using cgo.

Ian

[Alonso Vidales]

Ahh, ok, I was forgetting about the extern “C”, thanks a lot!