Float calculation error

[siguorui]

Floats cannot be added or subtracted directly. Because of the accuracy problem, calculation errors may occur. eg:

func TestIncrementFloat64(t *testing.T) { tc := New(DefaultExpiration, 0) tc.Set("float64", float64(0.6), DefaultExpiration) n, err := tc.IncrementFloat64("float64", 0.7) if err != nil { t.Error("Error incrementing:", err) } if n != 1.3 { t.Error("Returned number is not 1.3:", n) } x, found := tc.Get("float64") if !found { t.Error("float64 was not found") } if x.(float64) != 1.3 { t.Error("float64 is not 1.3:", x) } }

the result will be 1.2999999999999998.

func TestDecrementFloat64(t *testing.T) { tc := New(DefaultExpiration, 0) tc.Set("float64", float64(74.96), DefaultExpiration) n, err := tc.DecrementFloat64("float64", 20.48) if err != nil { t.Error("Error decrementing:", err) } if n != 54.48 { t.Error("Returned number is not 54.48:", n) } x, found := tc.Get("float64") if !found { t.Error("float64 was not found") } if x.(float64) != 54.48 { t.Error("float64 is not 54.48:", x) } }

the result will be 54.47999999999999