Function from_value 

pub fn from_value(value: &Value) -> Option<Value>

Convert a serde_json value to an immutable JSON value.

let data = r#"
        {
            "string": "string",
            "int": 43,
            "float": 5.8,
            "boolean": true,
            "object": {"test": "test"},
            "array": [
                "string",
                1,
                3.0,
                false,
                {"test": "test"},
                [1]
            ]
        }"#;

    let v: Value = serde_json::from_str(data)?;

    assert_eq!(Some(v.clone()), from_value(&v).and_then(|f| to_value(&f)));