merge

json_plus

Function merge 

Source 
pub fn merge(base: &mut Value, patch: &Value)
Expand description

merges the patch Value on top of the base.

use json_plus::merge;
use serde_json::json;

fn main() -> Result<(), Box<dyn std::error::Error>> {
   let mut base = json!({"key":"old value", "arr":[]});
   let patch = json!({"key2":"value 2"});

   merge(&mut base, &patch);
   println!("{}", base);
   Ok(())
}