That might be the dumbest Rustlang question ever but I promise I tried my best to find the answer in the documentation or any other place on the web.
I can convert a string to a vector of bytes like this:
let bar = bytes!("some string"); Unfortunately I can't do it this way
let foo = "some string"; let bar = bytes!(foo); Because bytes! expects a string literal.
But then, how do I get my foo converted into a vector of bytes?
(&str).as_bytes gives you a view of a string as a &[u8] byte slice (that can be called on String since that derefs to str, and there's also String.into_bytes will consume a String to give you a Vec<u8>.
Use the .as_bytes version if you don't need ownership of the bytes.
fn main() { let string = "foo"; println!("{:?}", string.as_bytes()); // prints [102, 111, 111] } BTW, The naming conventions for conversion functions are helpful in situations like these, because they allow you to know approximately what name you might be looking for.
bytes!(foo) in bar? I tried let bar = (&foo).as_bytes but that doesn't seem to do the trick.as_bytes on type &'static str
the trait `core::fmt::Display` is not implemented for the type `[u8]` [E0277]. Does that mean your answer needs to be updated to change {} with {:?}?
str and String. (Conceptually, it doesn't make any sense to talk about the "bytes of a string" without talking about encoding.)To expand the answers above. Here are a few different conversions between types.
&str to &[u8]:
let my_string: &str = "some string"; let my_bytes: &[u8] = my_string.as_bytes(); &str to Vec<u8>:
let my_string: &str = "some string"; let my_bytes: Vec<u8> = my_string.as_bytes().to_vec(); String to &[u8]:
let my_string: String = "some string".to_owned(); let my_bytes: &[u8] = my_string.as_bytes(); String to Vec<u8>:
let my_string: String = "some string".to_owned(); let my_bytes: Vec<u8> = my_string.into_bytes(); Specifying the variable type is optional in all cases. Just added to avoid confusion.
Playground link: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=5ad228e45a38b4f097bbbba49100ecfc
`let v1: Vec<u8> = string.encode_to_vec();` `let v2: &[u8] = string.as_bytes();` two work difference, in some of library use ownership of bytes !! if you use as_bytes() see compiler error: must be static.
for example: tokio_uring::fs::File::write_at() get a ownership of bytes !!
but if you need borrowing , use as_bytes()
