Attribute Macro main

#[main]

Available on attributes only.

Marks async function to be executed by selected runtime.

Options:

• basic_scheduler - All tasks are executed on the current thread.
• threaded_scheduler - Uses the multi-threaded scheduler. Used by default (requires rt-threaded feature).

Function arguments:

Arguments are allowed for any functions aside from main which is special

Usage

Using default

#[tokio::main]
async fn main() {
    println!("Hello world");
}

Select runtime

#[tokio::main(basic_scheduler)]
async fn main() {
    println!("Hello world");
}