use std::io;
#[cfg(feature = "snapshot")] use core::fmt;
#[cfg(feature = "snapshot")]
use serde::{Serialize, Deserialize, Serializer, Deserializer, de::{self, Visitor}};
#[derive(Debug)]
pub struct Sink(io::Sink);
#[derive(Debug)]
pub struct Empty(io::Empty);
impl Default for Sink {
fn default() -> Self {
Sink(io::sink())
}
}
impl Clone for Sink {
fn clone(&self) -> Self {
Self::default()
}
}
impl io::Write for Sink {
#[inline]
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.0.write(buf)
}
#[inline]
fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result<usize> {
self.0.write_vectored(bufs)
}
#[inline]
fn flush(&mut self) -> io::Result<()> {
self.0.flush()
}
}
impl io::Read for Empty {
#[inline]
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
}
impl io::BufRead for Empty {
#[inline]
fn fill_buf(&mut self) -> io::Result<&[u8]> {
self.0.fill_buf()
}
#[inline]
fn consume(&mut self, n: usize) {
self.0.consume(n)
}
}
impl Default for Empty {
fn default() -> Self {
Empty(io::empty())
}
}
impl Clone for Empty {
fn clone(&self) -> Self {
Self::default()
}
}
#[cfg(feature = "snapshot")]
macro_rules! impl_serde_unit {
($ty:ty, $name:expr) => {
impl Serialize for $ty {
fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
serializer.serialize_unit_struct($name)
}
}
impl<'de> Deserialize<'de> for $ty {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'de>
{
struct UnitVisitor;
impl<'de> Visitor<'de> for UnitVisitor {
type Value = $ty;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("unit")
}
fn visit_unit<E: de::Error>(self) -> Result<Self::Value, E> {
Ok(<$ty>::default())
}
}
deserializer.deserialize_unit_struct($name, UnitVisitor)
}
}
};
}
#[cfg(feature = "snapshot")]
impl_serde_unit!(Sink, "Sink");
#[cfg(feature = "snapshot")]
impl_serde_unit!(Empty, "Empty");