primitive_io.rs

use std::io::{self, Read, Write};

use num_traits::{FromBytes, ToBytes};

trait ReadPrimitive {
	fn read_le_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default;
	fn read_be_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default;
	fn read_ne_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default;
}

impl<T: io::Read> ReadPrimitive for T {
	fn read_le_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default,
	{
		let mut buf = Prim::Bytes::default();
		self.read_exact(buf.as_mut())?;
		Ok(Prim::from_le_bytes(&buf))
	}

	fn read_be_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default,
	{
		let mut buf = Prim::Bytes::default();
		self.read_exact(buf.as_mut())?;
		Ok(Prim::from_be_bytes(&buf))
	}

	fn read_ne_primitive<Prim: FromBytes>(&mut self) -> io::Result<Prim>
	where
		Prim::Bytes: Default,
	{
		let mut buf = Prim::Bytes::default();
		self.read_exact(buf.as_mut())?;
		Ok(Prim::from_ne_bytes(&buf))
	}
}

trait WritePrimitive {
	fn write_le_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()>;
	fn write_be_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()>;
	fn write_ne_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()>;
}

impl<T: io::Write> WritePrimitive for T {
	fn write_le_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()> {
		let bytes = v.to_le_bytes();
		self.write_all(bytes.as_ref())
	}

	fn write_be_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()> {
		let bytes = v.to_be_bytes();
		self.write_all(bytes.as_ref())
	}

	fn write_ne_primitive<Prim: ToBytes>(&mut self, v: Prim) -> io::Result<()> {
		let bytes = v.to_ne_bytes();
		self.write_all(bytes.as_ref())
	}
}