title: golang: can i share C.int between packages
body: <p>in the main package i have:</p>
  
  <pre><code>var foo C.int
  foo = 3
  t := fastergo.Ctuner_new()
  fastergo.Ctuner_register_parameter(t, &amp;foo, 0, 100, 1)
  </code></pre>
  
  <p>in the fastergo package i have:</p>
  
  <pre><code>func Ctuner_register_parameter(tuner unsafe.Pointer, parameter *C.int, from C.int, to C.int, step C.int) C.int {
      ...
  }
  </code></pre>
  
  <p>if i try to run it, i get:</p>
  
  <pre><code>demo.go:14[/tmp/go-build742221968/command-line-arguments/_obj/demo.cgo1.go:21]: cannot use &amp;foo (type *_Ctype_int) as type *fastergo._Ctype_int in function argument
  </code></pre>
  
  <p>i am not really sure what go is trying to tell me here, but somehow i think it wants to tell me, that all C.int are not equal? why is this the case? how can i solve this / work around?</p>