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Copy pathiterator.rs
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74 lines (65 loc) · 1.99 KB
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Copy pathiterator.rs
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74 lines (65 loc) · 1.99 KB
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// Copyright 2020-2022 Jorge C. Leitão
// Copyright 2021 Datafuse Labs
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::iter::TrustedLen;
use super::Buffer;
/// This crates' equivalent of [`std::vec::IntoIter`] for [`Buffer`].
#[derive(Debug, Clone)]
pub struct IntoIter<T: Copy> {
buffer: Buffer<T>,
current: *const T,
end: *const T,
}
impl<T: Copy> IntoIter<T> {
#[inline]
pub fn new(buffer: Buffer<T>) -> Self {
let ptr = buffer.as_ptr();
let len = buffer.len();
Self {
current: ptr,
end: unsafe { ptr.add(len) },
buffer,
}
}
}
impl<T: Copy> Iterator for IntoIter<T> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
if std::ptr::eq(self.current, self.end) {
None
} else {
let value = unsafe { *self.current };
self.current = unsafe { self.current.add(1) };
Some(value)
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = unsafe { self.end.offset_from(self.current) } as usize;
(len, Some(len))
}
}
impl<T: Copy> DoubleEndedIterator for IntoIter<T> {
#[inline]
fn next_back(&mut self) -> Option<Self::Item> {
if std::ptr::eq(self.current, self.end) {
None
} else {
self.end = unsafe { self.end.sub(1) };
Some(unsafe { *self.end })
}
}
}
unsafe impl<T: Copy> TrustedLen for IntoIter<T> {}