Marcus Chen

struct Config<'a> {
    name: &'a str,
    value: &'a str,
}

fn parse_config(line: &str) -> Config {

fn calculate_length(s: &String) -> usize {
    s.len()
}

fn append_suffix(s: &mut String) {
    s.push_str(" world");

fn take_ownership(s: String) {
    println!("Took ownership: {}", s);
} // s is dropped here

fn main() {
    let message = String::from("hello");

use anyhow::{Context, Result};
use std::fs;

fn load_config(path: &str) -> Result<String> {
    fs::read_to_string(path)
        .with_context(|| format!("failed to read config from {}", path))

use thiserror::Error;

#[derive(Error, Debug)]
pub enum ConfigError {
    #[error("file not found: {0}")]
    NotFound(String),

use std::fs;
use std::num::ParseIntError;

fn read_port(path: &str) -> Result<u16, Box<dyn std::error::Error>> {
    let contents = fs::read_to_string(path)?;
    let port: u16 = contents.trim().parse()?;