Rust MaybeUninit.write_slice用法及代码示例

本文简要介绍rust语言中 std::mem::MaybeUninit.write_slice 的用法。

用法

pub fn write_slice(this: &'a mut [MaybeUninit<T>], src: &[T]) -> &'a mut [T] where    T: Copy,

将元素从 src 复制到 this ，返回对现在初始化的 this 内容的可变引用。

如果 T 未实现 Copy ，请使用 write_slice_cloned

这类似于 slice::copy_from_slice 。

Panics

如果两个切片的长度不同，此函数将出现Panics。

例子

#![feature(maybe_uninit_write_slice)]
use std::mem::MaybeUninit;

let mut dst = [MaybeUninit::uninit(); 32];
let src = [0; 32];

let init = MaybeUninit::write_slice(&mut dst, &src);

assert_eq!(init, src);

#![feature(maybe_uninit_write_slice, vec_spare_capacity)]
use std::mem::MaybeUninit;

let mut vec = Vec::with_capacity(32);
let src = [0; 16];

MaybeUninit::write_slice(&mut vec.spare_capacity_mut()[..src.len()], &src);

// SAFETY: we have just copied all the elements of len into the spare capacity
// the first src.len() elements of the vec are valid now.
unsafe {
    vec.set_len(src.len());
}

assert_eq!(vec, src);

相关用法

注：本文由纯净天空筛选整理自rust-lang.org大神的英文原创作品 std::mem::MaybeUninit.write_slice。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。