OPENSSL_sk_copy_func typedef
OPENSSL_sk_copy_func is a function that copies an element in a stack. Note
its actual type is T ()(const T *) for some T. Low-level sk_* functions
will be passed a type-specific wrapper to call it correctly.
Implementation
typedef OPENSSL_sk_copy_func =
ffi.Pointer<ffi.NativeFunction<OPENSSL_sk_copy_funcFunction>>;