You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/phaser/phaser/vendor/serde_json/src/value
    
    the code of the file until where you have to start completion: //! The Value enum, a loosely typed way of representing any valid JSON value.
//!
//! # Constructing JSON
//!
//! Serde JSON provides a [`json!` macro]
    
//! fn main() {
//!     // The type of `john` is `serde_json::Value`
//!     let john = json!({
//!         "name": "John Doe",
//!         "age": 43,
//!         "phones": [
//!             "+44 1234567",
//!             "+44 2345678"
//!         ]
//!     });
//!
//!     println!("first phone number: {}", john["phones"][0]);
//!
//!     // Convert to a string of JSON and print it out
//!     println!("{}", john.to_string());
//! }