On Wednesday, 23 January 2013 at 16:33:08 UTC, Sarath Kumar wrote:
DMD v2.61; openSUSE 12.1
Source:
-------
libA.d:
module libA;
extern (C)
{
struct Opaque;
Opaque* getObject();
void doSomething(Opaque *);
}
----------
libB.d:
module libB;
extern (C)
{
struct Opaque;
void doAction(Opaque *);
}
-----------
bug.d
import libA, libB;
int main(string[] args)
{
auto opaque = libA.getObject();
libA.doSomething(opaque); // this is okay
libB.doAction(opaque); // but this is not, compiler
error here
return 0;
}
When I compile the above files, I get the below error.
$ rdmd bug.d
bug.d(7): Error: function libB.doAction (Opaque*) is not
callable using argument types (Opaque*)
bug.d(7): Error: cannot implicitly convert expression (opaque)
of type Opaque* to Opaque*
If I do an explicit cast, libB.Opaque*, for opaque in line 7,
bug.d, I get completely different set of errors.
$ rdmd bug.d
libB.d(5): Error: struct libB.Opaque unknown size
libB.d(5): Error: struct libB.Opaque no size yet for forward
reference
libB.d(5): Error: struct libB.Opaque unknown size
libB.d(5): Error: struct libB.Opaque no size yet for forward
reference
libA.d(5): Error: struct libA.Opaque unknown size
libA.d(5): Error: struct libA.Opaque no size yet for forward
reference
Can someone please tell me the right way to pass an opaque
object between module's functions.
The error message here is deceiving. Declare the struct in one
module only and then import it in every module that uses it. So,
for example, keep the declaration in libA, remove it from libB
and in libB add "import libA;".
