extern crate rand;
use rand::Rng;
let mut rng = rand::thread_rng();
let x = rng.gen::<f32>();//x belong to [0,1)
秒表
use std::time::SystemTime;
let start_time = SystemTime::now();
//workload code
let end_time = SystemTime::now();
let difference = end_time.duration_since(start_time)
.expect("SystemTime::duration_since failed");
println!("{:?}", difference);
写文件
use std::io::prelude::*;
use std::fs::File;
let mut file = File::create("a.txt").expect("Cannot create file");
file.write_all(String::from("content").as_bytes()).expect("Cannot write file");
//file.write_all(b"content").expect("Cannot write file");
字符串编码
use encoding::{Encoding, DecoderTrap};
use encoding::all::WINDOWS_31J;
let mut model_name = [0u8; 10];
file.read(&mut model_name).unwrap();
let s = WINDOWS_31J.decode(&model_name, DecoderTrap::Ignore);
大小端
use byteorder::{LittleEndian, ReadBytesExt};
file.read_f32::<LittleEndian>().unwrap();