E0137 - Error codes index
Description: Book listing all Rust error codes

# Error code E0137

#### Note: this error code is no longer emitted by the compiler.

More than one function was declared with the `#[main]` attribute.

Erroneous code example:

    #![allow(unused)]
    #![feature(main)]

    fn main() {
    #[main]
    fn foo() {}

    #[main]
    fn f() {} // error: multiple functions with a `#[main]` attribute
    }

This error indicates that the compiler found multiple functions with the `#[main]` attribute. This is an error because there must be a unique entry point into a Rust program. Example:

    #![allow(unused)]
    #![feature(main)]

    fn main() {
    #[main]
    fn f() {} // ok!
    }