src/tools/clippy/clippy_lints/src/types/option_option.rs

   1 use rustc_hir::{self as hir, def_id::DefId, QPath};
   2 use rustc_lint::LateContext;
   3 use rustc_span::symbol::sym;
   4
   5 use crate::utils::{is_ty_param_diagnostic_item, span_lint};
   6
   7 use super::OPTION_OPTION;
   8
   9 pub(super) fn check(cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>, qpath: &QPath<'_>, def_id: DefId) -> bool {
  10     if cx.tcx.is_diagnostic_item(sym::option_type, def_id)
  11         && is_ty_param_diagnostic_item(cx, qpath, sym::option_type).is_some()
  12     {
  13         span_lint(
  14             cx,
  15             OPTION_OPTION,
  16             hir_ty.span,
  17             "consider using `Option<T>` instead of `Option<Option<T>>` or a custom \
  18                                  enum if you need to distinguish all 3 cases",
  19         );
  20         true
  21     } else {
  22         false
  23     }
  24 }