backend_tests.py 文件源码

def test_enum(self):
        ffi = FFI(backend=self.Backend())
        ffi.cdef("enum foo { A0, B0, CC0, D0 };")
        assert ffi.string(ffi.cast("enum foo", 0)) == "A0"
        assert ffi.string(ffi.cast("enum foo", 2)) == "CC0"
        assert ffi.string(ffi.cast("enum foo", 3)) == "D0"
        assert ffi.string(ffi.cast("enum foo", 4)) == "4"
        ffi.cdef("enum bar { A1, B1=-2, CC1, D1, E1 };")
        assert ffi.string(ffi.cast("enum bar", 0)) == "A1"
        assert ffi.string(ffi.cast("enum bar", -2)) == "B1"
        assert ffi.string(ffi.cast("enum bar", -1)) == "CC1"
        assert ffi.string(ffi.cast("enum bar", 1)) == "E1"
        assert ffi.cast("enum bar", -2) != ffi.cast("enum bar", -2)
        assert ffi.cast("enum foo", 0) != ffi.cast("enum bar", 0)
        assert ffi.cast("enum bar", 0) != ffi.cast("int", 0)
        assert repr(ffi.cast("enum bar", -1)) == "<cdata 'enum bar' -1: CC1>"
        assert repr(ffi.cast("enum foo", -1)) == (  # enums are unsigned, if
            "<cdata 'enum foo' 4294967295>")        # they contain no neg value
        ffi.cdef("enum baz { A2=0x1000, B2=0x2000 };")
        assert ffi.string(ffi.cast("enum baz", 0x1000)) == "A2"
        assert ffi.string(ffi.cast("enum baz", 0x2000)) == "B2"