Regression on float serialization

[gcandal]

With 0.6 , the serialization of floats changed. When serializing 0.1, the results are:

• Before, with 0.5: 0.1. Relied on Display
• Now, with 0.6: 0.10000000149011612. Relies on serde

Using a number that can be precisely represented as a float, like 0.0625, yields the same result for both versions.

I don't know if this is something you want to do, but serde_json uses a custom formatter that relies on ryu for this.

Related to this, but on the deserialization side, serde_json offers two alternative features which you might want to give a look.