//! lint when there is an enum with no variants
-use crate::utils::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_help;
use rustc_hir::{Item, ItemKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Checks for `enum`s with no variants.
+ /// ### What it does
+ /// Checks for `enum`s with no variants.
///
/// As of this writing, the `never_type` is still a
/// nightly-only experimental API. Therefore, this lint is only triggered
/// if the `never_type` is enabled.
///
- /// **Why is this bad?** If you want to introduce a type which
+ /// ### Why is this bad?
+ /// If you want to introduce a type which
/// can't be instantiated, you should use `!` (the primitive type "never"),
/// or a wrapper around it, because `!` has more extensive
/// compiler support (type inference, etc...) and wrappers
/// For further information visit [never type documentation](https://doc.rust-lang.org/std/primitive.never.html)
///
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// Bad:
/// ```rust
/// enum Test {}
///
/// struct Test(!);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub EMPTY_ENUM,
pedantic,
"enum with no variants"
return;
}
- let did = cx.tcx.hir().local_def_id(item.hir_id);
if let ItemKind::Enum(..) = item.kind {
- let ty = cx.tcx.type_of(did);
+ let ty = cx.tcx.type_of(item.def_id);
let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
if adt.variants.is_empty() {
span_lint_and_help(