struct MyStruct {}

#[cfg(target_arch = "x86")]
impl MyStruct {
    fn foo() {
        println!("x86");
    }
}

#[cfg(target_arch = "x86_64")]
impl MyStruct {
    fn foo() {
        println!("x86_64");
    }
}

#[cfg(target_arch = "arm")]
impl MyStruct {
    fn foo() {
        println!("arm");
    }
}

#[cfg(target_arch = "aarch64")]
impl MyStruct {
    fn foo() {
        println!("aarch64");
    }
}

fn main() {
    MyStruct::foo();
}