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//! This library provides miscellaneous functionalities to help asynchronous operations in Rust.
//!
//! `handy_async` uses [futures](https://github.com/alexcrichton/futures-rs) to
//! achieve asynchronous operations (mainly I/O related operations)
//! and defines a lot of pattern objects to facilitate writing declarative code.
//!
//! For example, you can write a function to read a TCP header
//! defined in [RFC-793](https://www.ietf.org/rfc/rfc793.txt) asynchronously as following.
//!
//! ```no_run
//! extern crate handy_async;
//! extern crate futures;
//!
//! use std::io::{Read, Error};
//! use futures::{Future, BoxFuture};
//! use handy_async::io::ReadFrom;
//! use handy_async::pattern::{Pattern, Endian};
//! use handy_async::pattern::read::{U16, U32};
//!
//! struct TcpHeader {
//! source_port: u16,
//! destination_port: u16,
//! sequence_number: u32,
//! acknowledgment_number: u32,
//! data_offset: u8, // 4 bits
//! reserved: u8, // 6 bits
//! flags: u8, // 6 bits
//! window: u16,
//! checksum: u16,
//! urgent_pointer: u16,
//! option: Vec<u8>,
//! }
//!
//! fn read_tcp_header<R: Read + Send + 'static>(reader: R) -> BoxFuture<TcpHeader, Error> {
//! let pattern = (U16.be(), U16.be(), U32.be(), U32.be(),
//! U16.be(), U16.be(), U16.be(), U16.be())
//! .and_then(|(src_port, dst_port, seq_num, ack_num, flags, window, checksum, urgent)| {
//! let data_offset = (flags & 0b1111) as u8;
//! let header = TcpHeader {
//! source_port: src_port,
//! destination_port: dst_port,
//! sequence_number: seq_num,
//! acknowledgment_number: ack_num,
//! data_offset: data_offset,
//! reserved: ((flags >> 4) & 0b111111) as u8,
//! flags: (flags >> 10) as u8,
//! window: window,
//! checksum: checksum,
//! urgent_pointer: urgent,
//! option: Vec::new(),
//! };
//!
//! let option_size = (data_offset as usize - 5) * 4;
//! (Ok(header), vec![0; option_size]) // Reads additional option bytes
//! })
//! .map(|(mut header, option)| {
//! header.option = option;
//! header
//! });
//! pattern.read_from(reader).map(|(reader, header)| header).map_err(|e| e.into_error()).boxed()
//! }
//!
//! fn main(){
//! let future = read_tcp_header(std::io::stdin());
//! let tcp_header = future.wait().expect("Failed to read tcp header");
//! }
//! ```
extern crate futures;
extern crate byteorder;