src/tools/clippy/clippy_lints/src/casts/cast_enum_constructor.rs

   1 use clippy_utils::diagnostics::span_lint;
   2 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
   3 use rustc_hir::{Expr, ExprKind};
   4 use rustc_lint::LateContext;
   5 use rustc_middle::ty::{self, Ty};
   6
   7 use super::CAST_ENUM_CONSTRUCTOR;
   8
   9 pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>, cast_from: Ty<'_>) {
  10     if matches!(cast_from.kind(), ty::FnDef(..))
  11         && let ExprKind::Path(path) = &cast_expr.kind
  12         && let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), _) = cx.qpath_res(path, cast_expr.hir_id)
  13     {
  14         span_lint(
  15             cx,
  16             CAST_ENUM_CONSTRUCTOR,
  17             expr.span,
  18             "cast of an enum tuple constructor to an integer",
  19         );
  20     }
  21 }