backend_tests.py 文件源码

def test_float(self):
        ffi = FFI(backend=self.Backend())
        p = ffi.new("float[]", [-2, -2.5])
        assert p[0] == -2.0
        assert p[1] == -2.5
        p[1] += 17.75
        assert p[1] == 15.25
        #
        p = ffi.new("float*", 15.75)
        assert p[0] == 15.75
        py.test.raises(TypeError, int, p)
        py.test.raises(TypeError, float, p)
        p[0] = 0.0
        assert bool(p) is True
        #
        p = ffi.new("float*", 1.1)
        f = p[0]
        assert f != 1.1      # because of rounding effect
        assert abs(f - 1.1) < 1E-7
        #
        INF = 1E200 * 1E200
        assert 1E200 != INF
        p[0] = 1E200
        assert p[0] == INF     # infinite, not enough precision