src/tools/clippy/clippy_lints/src/loops/explicit_into_iter_loop.rs

   1 use super::EXPLICIT_INTO_ITER_LOOP;
   2 use clippy_utils::diagnostics::span_lint_and_sugg;
   3 use clippy_utils::is_trait_method;
   4 use clippy_utils::source::snippet_with_applicability;
   5 use rustc_errors::Applicability;
   6 use rustc_hir::Expr;
   7 use rustc_lint::LateContext;
   8 use rustc_middle::ty::TyS;
   9 use rustc_span::symbol::sym;
  10
  11 pub(super) fn check(cx: &LateContext<'_>, self_arg: &'hir Expr<'hir>, call_expr: &Expr<'_>) {
  12     let self_ty = cx.typeck_results().expr_ty(self_arg);
  13     let self_ty_adjusted = cx.typeck_results().expr_ty_adjusted(self_arg);
  14     if !(TyS::same_type(self_ty, self_ty_adjusted) && is_trait_method(cx, call_expr, sym::IntoIterator)) {
  15         return;
  16     }
  17
  18     let mut applicability = Applicability::MachineApplicable;
  19     let object = snippet_with_applicability(cx, self_arg.span, "_", &mut applicability);
  20     span_lint_and_sugg(
  21         cx,
  22         EXPLICIT_INTO_ITER_LOOP,
  23         call_expr.span,
  24         "it is more concise to loop over containers instead of using explicit \
  25             iteration methods",
  26         "to write this more concisely, try",
  27         object.to_string(),
  28         applicability,
  29     );
  30 }