Function serde_json::to_writer_pretty

pub fn to_writer_pretty<W: ?Sized, T: ?Sized>(
    writer: &mut W, 
    value: &T
) -> Result<()> where
    W: Write,
    T: Serialize, 

Serialize the given data structure as pretty-printed JSON into the IO stream.

Serialization can fail if T's implementation of Serialize decides to fail, or if T contains a map with non-string keys.