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// edition:2018
// aux-build:test-macros.rs
// aux-build:derive-helper-shadowing.rs
#[macro_use]
extern crate test_macros;
#[macro_use]
extern crate derive_helper_shadowing;
use test_macros::empty_attr as empty_helper;
macro_rules! gen_helper_use {
() => {
#[empty_helper] //~ ERROR cannot find attribute `empty_helper` in this scope
struct W;
}
}
#[empty_helper] //~ ERROR `empty_helper` is ambiguous
//~| WARN derive helper attribute is used before it is introduced
//~| WARN this was previously accepted
#[derive(Empty)]
struct S {
#[empty_helper] // OK, no ambiguity, derive helpers have highest priority
field: [u8; {
use empty_helper; //~ ERROR `empty_helper` is ambiguous
#[empty_helper] // OK, no ambiguity, derive helpers have highest priority
struct U;
mod inner {
// OK, no ambiguity, the non-helper attribute is not in scope here, only the helper.
#[empty_helper]
struct V;
gen_helper_use!();
#[derive(GenHelperUse)] //~ ERROR cannot find attribute `empty_helper` in this scope
struct Owo;
use empty_helper as renamed;
#[renamed] //~ ERROR cannot use a derive helper attribute through an import
struct Wow;
}
0
}]
}
// OK, no ambiguity, only the non-helper attribute is in scope.
#[empty_helper]
struct Z;
fn main() {
let s = S { field: [] };
}
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