gcc/testsuite/rust/compile/torture/function_reference2.rs

#![feature(no_core)]
#![no_core]

fn test(a: i32) -> i32 {
    a + 1
}

fn main() {
    let a: fn(i32) -> i32 = test;
    let b = a(1);
    // { dg-warning "unused name" "" { target *-*-* } .-1 }
}