Crate all_the_same
source ·Expand description
If you ever had code that looks like this:
use std::io;
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::io::AsyncWrite;
use tokio::net::{TcpStream, UnixStream};
enum Stream {
Tcp(TcpStream),
Unix(UnixStream),
Custom(Box<dyn AsyncWrite + Unpin + 'static>),
}
impl AsyncWrite for Stream {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, io::Error>> {
match self.get_mut() {
Stream::Tcp(s) => Pin::new(s).poll_write(cx, buf),
Stream::Unix(s) => Pin::new(s).poll_write(cx, buf),
Stream::Custom(s) => Pin::new(s).poll_write(cx, buf),
}
}
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), io::Error>> {
match self.get_mut() {
Stream::Tcp(s) => Pin::new(s).poll_shutdown(cx),
Stream::Unix(s) => Pin::new(s).poll_shutdown(cx),
Stream::Custom(s) => Pin::new(s).poll_shutdown(cx),
}
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
match self.get_mut() {
Stream::Tcp(s) => Pin::new(s).poll_flush(cx),
Stream::Unix(s) => Pin::new(s).poll_flush(cx),
Stream::Custom(s) => Pin::new(s).poll_flush(cx),
}
}
}
with the help of the macro you can now replace it with:
use std::io;
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::io::AsyncWrite;
use tokio::net::{TcpStream, UnixStream};
use all_the_same::all_the_same;
enum Stream {
Tcp(TcpStream),
Unix(UnixStream),
Custom(Box<dyn AsyncWrite + Unpin + 'static>),
}
impl AsyncWrite for Stream {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, io::Error>> {
all_the_same!(match self.get_mut() {
Stream::[Tcp, Unix, Custom](s) => Pin::new(s).poll_write(cx, buf)
})
}
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), io::Error>> {
all_the_same!(match self.get_mut() {
Stream::[Tcp, Unix, Custom](s) => Pin::new(s).poll_shutdown(cx)
})
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
all_the_same!(match self.get_mut() {
Stream::[Tcp, Unix, Custom](s) => Pin::new(s).poll_flush(cx)
})
}
}
§Feature gated enum variants, etc.
Btw, you can add attributes that will be applied to the match arms, to deal with feature-gated enum variants:
use all_the_same::all_the_same;
enum Variants {
Foo(String),
#[cfg(test)]
Bar(String)
}
impl Variants {
pub fn value(&self) -> &str {
all_the_same!(match self {
Self::[Foo, #[cfg(test)]Bar](v) => v
})
}
}
Macros§
- The macro itself.