Let's write a test for this as well, and investigate if the other function also needs this (update: it does, see commit below).

Let's write a test for this as well, and investigate if the other function also needs this (update: it does, see commit below).

Hey I tested it and its not working,
return ctypes.addressof(cptr)
TypeError: invalid type

Proposal:
@certik

def cptr_to_u64(cptr):
    return u64(ctypes.cast(cptr, ctypes.c_void_p).value)

def u64_to_cptr(ivalue):
    return ctypes.c_void_p(i64(ivalue))

Tested and works

@ronnuriel, awesome thanks. I submitted it here with you as an author: #2186. It would be nice to figure out an isolated test for this but it's more important to fix it, so if it passes, we'll merge it. Closing in favor of #2186.