Module: Type

These types are meant to be used in NativeCall and Callable.

Floats

Python type: int

F32

F64

Unsigned

Python type: int

U8

U16

U32

U64

U128

Signed

Python type: int

I8

I16

I32

I64

I128

Strings

CStr

Python type: str

When received as a Callback argument or a NativeCall return, it’s a python string without null terminator. When used as a NativeCall argument and Callback return, you MUST include a null terminator in the string.

WStr

NativeCall return type / Callback argument: int (pointer to address)

NativeCall argument / Callback return type: WStr

This may or may not be null terminated, depends on api requirements. Some functions require you to pass a length, sometimes it needs to be null terminated. This is up to you to manage according to the api.

On a Callback, an argument of this type will be a ptr. On a NativeCall, a return of this type will be a ptr. In order to convert the ptr into a string you can use, see WStr.

To return a WStr from a Callback, or give a WStr argument to a NativeCall, use WStr.

Chars

Python type: str

Char

Python type: str (1 character that can fit in a u8)

1 byte

WChar

Python type: str (1 character that can fit in a u16)

2 bytes

Misc

Ptr

Python type: int

Bool

Python type: boolean

Struct(size: int)

Python type: bytes

This is a by-value struct (not a ptr to a struct). You can use this type in arg or return position to indicate receiving or returning a struct by value.

Example

import cffi

def foo(arg: int):
    pass

c = cffi.Callable(foo, cffi.Types.U64)