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use std::io::{Read, Seek, SeekFrom};
use Result;
pub trait Tape: Read + Seek + Sized {
#[doc(hidden)]
fn count(&mut self) -> Result<u64> {
let current = try!(self.position());
let end = self.seek(SeekFrom::End(0));
try!(self.jump(current));
end
}
#[doc(hidden)]
#[inline]
fn jump(&mut self, position: u64) -> Result<u64> {
self.seek(SeekFrom::Start(position))
}
#[doc(hidden)]
fn peek<T: Value>(&mut self) -> Result<T> {
let current = try!(self.position());
let result = Value::read(self);
try!(self.jump(current));
result
}
#[doc(hidden)]
#[inline]
fn position(&mut self) -> Result<u64> {
self.seek(SeekFrom::Current(0))
}
#[doc(hidden)]
#[inline(always)]
fn take<T: Value>(&mut self) -> Result<T> {
Value::read(self)
}
}
pub trait Value: Sized {
fn read<T: Tape>(&mut T) -> Result<Self>;
}
pub trait ValueExt<P>: Sized {
fn read<T: Tape>(&mut T, P) -> Result<Self>;
}
impl<T: Read + Seek> Tape for T {
}