Small string in Rust

sso.rs

use std::mem;
use std::fmt::Write;

fn dump_bytes<T>(val: &T) -> String {
  let mut output = String::new();

  let bytes = unsafe {
    let pointer: *const u8 = std::mem::transmute(val);
    std::slice::from_raw_parts(pointer, std::mem::size_of::<T>())
  };

  for byte in bytes {
      match *byte {
          32...128 => { output.push(*byte as char); },
          x        => { let _ = write!(&mut output, "({})", x); },
      }
  }

  output
}

fn dump_qwords<T>(val: &T) -> String {
  let qwords = unsafe {
    let pointer: *const u64 = std::mem::transmute(val);
    std::slice::from_raw_parts(pointer, std::mem::size_of::<T>() / 8)
  };
  qwords.iter().map(|&qword| format!("{:016x}", qword)).collect::<Vec<_>>().connect(" ")
}

enum StringContainer {
    EmbeddedASCII([u8; 47]),
    StaticRef(&'static str),
    Owned(String),
}

fn main() {
    let items = vec![
        StringContainer::Owned("foo".to_string()),
        StringContainer::EmbeddedASCII([65; 47]),
        StringContainer::StaticRef("foo")
    ];

    for item in &items {
        println!("-");
        println!("Size: {} bytes", mem::size_of_val(item));
        println!("bytes(x) = {}", dump_bytes(item));
        println!("qwords(x) = {}", dump_qwords(item));
    }
}