config.rs

extern crate serialize;
extern crate std;
extern crate collections;

use self::serialize::json;
use self::serialize::json::Json;
use self::std::io::File;
use self::collections::TreeMap;


pub fn load_config_map() -> Option<&TreeMap<~str, Json>> {
    let config: Json = match json::from_reader(&mut File::open(&Path::new("config.json"))) {
        Ok(v) => v,
        Err(e) => fail!("Failed to decode config: {}", e)
    };
    let config_map: &TreeMap<~str, Json> = match config.as_object() {
        Some(v) => v,
        None => fail!("Config isn't an object!")
    };
    return Some(config_map);
}

error.md

I'm getting this error when compiling:

src/config.rs:16:50: 16:56 error: `config` does not live long enough
src/config.rs:16     let config_map: &TreeMap<~str, Json> = match config.as_object() {
                                                                  ^~~~~~
src/config.rs:11:58: 21:2 note: reference must be valid for the anonymous lifetime #1 defined on the block at 11:57...
src/config.rs:11 pub fn load_config_map() -> Option<&TreeMap<~str, Json>> {
src/config.rs:12     let config: Json = match json::from_reader(&mut File::open(&Path::new("config.json"))) {
src/config.rs:13         Ok(v) => v,
src/config.rs:14         Err(e) => fail!("Failed to decode config: {}", e)
src/config.rs:15     };
src/config.rs:16     let config_map: &TreeMap<~str, Json> = match config.as_object() {
                 ...
src/config.rs:11:58: 21:2 note: ...but borrowed value is only valid for the block at 11:57
src/config.rs:11 pub fn load_config_map() -> Option<&TreeMap<~str, Json>> {
src/config.rs:12     let config: Json = match json::from_reader(&mut File::open(&Path::new("config.json"))) {
src/config.rs:13         Ok(v) => v,
src/config.rs:14         Err(e) => fail!("Failed to decode config: {}", e)
src/config.rs:15     };
src/config.rs:16     let config_map: &TreeMap<~str, Json> = match config.as_object() {
                 ...
error: aborting due to previous error