src/tools/clippy/clippy_lints/src/methods/iter_cloned_collect.rs

   1 use crate::methods::utils::derefs_to_slice;
   2 use clippy_utils::diagnostics::span_lint_and_sugg;
   3 use clippy_utils::ty::is_type_diagnostic_item;
   4 use if_chain::if_chain;
   5 use rustc_errors::Applicability;
   6 use rustc_hir as hir;
   7 use rustc_lint::LateContext;
   8 use rustc_span::sym;
   9
  10 use super::ITER_CLONED_COLLECT;
  11
  12 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, method_name: &str, expr: &hir::Expr<'_>, recv: &'tcx hir::Expr<'_>) {
  13     if_chain! {
  14         if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec);
  15         if let Some(slice) = derefs_to_slice(cx, recv, cx.typeck_results().expr_ty(recv));
  16         if let Some(to_replace) = expr.span.trim_start(slice.span.source_callsite());
  17
  18         then {
  19             span_lint_and_sugg(
  20                 cx,
  21                 ITER_CLONED_COLLECT,
  22                 to_replace,
  23                 &format!("called `iter().{method_name}().collect()` on a slice to create a `Vec`. Calling `to_vec()` is both faster and \
  24                 more readable"),
  25                 "try",
  26                 ".to_vec()".to_string(),
  27                 Applicability::MachineApplicable,
  28             );
  29         }
  30     }
  31 }