Rust 使用变量而不在线程中借用或克隆它

Question

I have a problem writing to files in actix web. When I want to write to files I need to place that in a thread, but then it is trying to clone files and is borrowing the form, which causes a lifetime error. How can I fix that. How can I use a variable within a thread without borrowing it.

for content in &form.files {
        let mut file = process_file(
            content.content_type.clone(),uuid.clone(),
        )?;
        web::block(move || file.write_all(&content.bytes))
            .await
            .map_err(ApiError::error)?
            .map_err(ApiError::error)?;
    }

Answer 1

You provide no actual reproduction case, no error message, and only a small part of the code, making investigation difficult as most SO readers are not psychic.

But I would assume the issue is this:

for content in &form.files {

form.files is probably something like a vec, meaning here content is already a borrow.

You need to move content out of the collection instead, assuming you cannot just move form.files itself, that means you need either some sort of draining iterator similar to Vec::drain , or you need to manually pop the items out of the collection.