rust/library/core/src/slice/specialize.rs

58 lines
1.3 KiB
Rust

use crate::ptr::write_bytes;
pub(super) trait SpecFill<T> {
fn spec_fill(&mut self, value: T);
}
impl<T: Clone> SpecFill<T> for [T] {
default fn spec_fill(&mut self, value: T) {
if let Some((last, elems)) = self.split_last_mut() {
for el in elems {
el.clone_from(&value);
}
*last = value
}
}
}
impl<T: Copy> SpecFill<T> for [T] {
default fn spec_fill(&mut self, value: T) {
for item in self.iter_mut() {
*item = value;
}
}
}
impl SpecFill<u8> for [u8] {
fn spec_fill(&mut self, value: u8) {
// SAFETY: this is slice of u8
unsafe {
let ptr = self.as_mut_ptr();
let len = self.len();
write_bytes(ptr, value, len);
}
}
}
impl SpecFill<i8> for [i8] {
fn spec_fill(&mut self, value: i8) {
// SAFETY: this is slice of i8
unsafe {
let ptr = self.as_mut_ptr();
let len = self.len();
write_bytes(ptr, value as u8, len);
}
}
}
impl SpecFill<bool> for [bool] {
fn spec_fill(&mut self, value: bool) {
// SAFETY: this is slice of bool
unsafe {
let ptr = self.as_mut_ptr();
let len = self.len();
write_bytes(ptr, value as u8, len);
}
}
}