rust/src/libsyntax/owned_slice.rs
Felix S. Klock II 0d5bcb14ad Switched to Box::new in many places.
Many of the modifications putting in `Box::new` calls also include a
pointer to Issue 22405, which tracks going back to `box <expr>` if
possible in the future.

(Still tried to use `Box<_>` where it sufficed; thus some tests still
have `box_syntax` enabled, as they use a mix of `box` and `Box::new`.)

Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
2015-03-03 21:05:55 +01:00

99 lines
2.5 KiB
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::default::Default;
use std::fmt;
use std::iter::{IntoIterator, FromIterator};
use std::ops::Deref;
use std::vec;
use serialize::{Encodable, Decodable, Encoder, Decoder};
/// A non-growable owned slice. This is a separate type to allow the
/// representation to change.
#[derive(Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct OwnedSlice<T> {
data: Box<[T]>
}
impl<T:fmt::Debug> fmt::Debug for OwnedSlice<T> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
self.data.fmt(fmt)
}
}
impl<T> OwnedSlice<T> {
pub fn empty() -> OwnedSlice<T> {
OwnedSlice { data: Box::new([]) }
}
#[inline(never)]
pub fn from_vec(v: Vec<T>) -> OwnedSlice<T> {
OwnedSlice { data: v.into_boxed_slice() }
}
#[inline(never)]
pub fn into_vec(self) -> Vec<T> {
self.data.into_vec()
}
pub fn as_slice<'a>(&'a self) -> &'a [T] {
&*self.data
}
pub fn move_iter(self) -> vec::IntoIter<T> {
self.into_vec().into_iter()
}
pub fn map<U, F: FnMut(&T) -> U>(&self, f: F) -> OwnedSlice<U> {
self.iter().map(f).collect()
}
}
impl<T> Deref for OwnedSlice<T> {
type Target = [T];
fn deref(&self) -> &[T] {
self.as_slice()
}
}
impl<T> Default for OwnedSlice<T> {
fn default() -> OwnedSlice<T> {
OwnedSlice::empty()
}
}
impl<T: Clone> Clone for OwnedSlice<T> {
fn clone(&self) -> OwnedSlice<T> {
OwnedSlice::from_vec(self.to_vec())
}
}
impl<T> FromIterator<T> for OwnedSlice<T> {
fn from_iter<I: IntoIterator<Item=T>>(iter: I) -> OwnedSlice<T> {
OwnedSlice::from_vec(iter.into_iter().collect())
}
}
impl<T: Encodable> Encodable for OwnedSlice<T> {
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
Encodable::encode(&**self, s)
}
}
impl<T: Decodable> Decodable for OwnedSlice<T> {
fn decode<D: Decoder>(d: &mut D) -> Result<OwnedSlice<T>, D::Error> {
Ok(OwnedSlice::from_vec(match Decodable::decode(d) {
Ok(t) => t,
Err(e) => return Err(e)
}))
}
}