我有一个大小未知的字节缓冲区,并且我想创建一个指向缓冲区开头内存的本地结构变量。按照在C语言中的做法,我在Rust中尝试了很多不同的方法,但一直遇到错误。这是我最新的尝试:
我遇到一个错误。
use std::mem::{size_of, transmute};
#[repr(C, packed)]
struct MyStruct {
foo: u16,
bar: u8,
}
fn main() {
let v: Vec<u8> = vec![1, 2, 3];
let buffer = v.as_slice();
let s: MyStruct = unsafe { transmute(buffer[..size_of::<MyStruct>()]) };
}
我遇到一个错误。
error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
--> src/main.rs:12:42
|
12 | let s: MyStruct = unsafe { transmute(buffer[..size_of::<MyStruct>()]) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
|
= help: the trait `std::marker::Sized` is not implemented for `[u8]`
= note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
transmute
需要在编译时知道大小。使用*mut
指针的解决方案看起来就像你必须这样做。 - Peter Hall