I found this code snippet in the help of python 2.7.5, which is a chapter about exposing a C-API to other modules in the Extending Python with C and C++ section: Providing a C API for an Extension Module
/* C API functions */
#define PySpam_System_NUM 0
#define PySpam_System_RETURN int
#define PySpam_System_PROTO (const char *command)
// ...
static PySpam_System_RETURN PySpam_System PySpam_System_PROTO;
// ...
static void **PySpam_API;
#define PySpam_System \
(*(PySpam_System_RETURN (*)PySpam_System_PROTO) PySpam_API[PySpam_System_NUM])
This snipped is for function capsules. A capsule is used to pass functions between two modules.
But what's the meaning of this snippet: [...] (PySpam_SystemRETURN (*)PySpam_System_PROTO) [...].
I think it's something like a static cast. Something like (int(*)(char s)). But what's the meaning of this construct?