Function to_writer 

pub fn to_writer<T: Serialize, W: Write>(
    value: &T,
    writer: &mut W,
) -> Result<()>

Serialize the given data structure as MASON into the I/O stream.

Serialization guarantees it only feeds valid UTF-8 sequences to the writer.

Errors

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