diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/get_first.rs')
-rw-r--r-- | src/tools/clippy/clippy_lints/src/get_first.rs | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/src/tools/clippy/clippy_lints/src/get_first.rs b/src/tools/clippy/clippy_lints/src/get_first.rs deleted file mode 100644 index 529f7baba..000000000 --- a/src/tools/clippy/clippy_lints/src/get_first.rs +++ /dev/null @@ -1,68 +0,0 @@ -use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::source::snippet_with_applicability; -use clippy_utils::{is_slice_of_primitives, match_def_path, paths}; -use if_chain::if_chain; -use rustc_ast::LitKind; -use rustc_errors::Applicability; -use rustc_hir as hir; -use rustc_lint::{LateContext, LateLintPass}; -use rustc_session::{declare_lint_pass, declare_tool_lint}; -use rustc_span::source_map::Spanned; - -declare_clippy_lint! { - /// ### What it does - /// Checks for using `x.get(0)` instead of - /// `x.first()`. - /// - /// ### Why is this bad? - /// Using `x.first()` is easier to read and has the same - /// result. - /// - /// ### Example - /// ```rust - /// let x = vec![2, 3, 5]; - /// let first_element = x.get(0); - /// ``` - /// - /// Use instead: - /// ```rust - /// let x = vec![2, 3, 5]; - /// let first_element = x.first(); - /// ``` - #[clippy::version = "1.63.0"] - pub GET_FIRST, - style, - "Using `x.get(0)` when `x.first()` is simpler" -} -declare_lint_pass!(GetFirst => [GET_FIRST]); - -impl<'tcx> LateLintPass<'tcx> for GetFirst { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if_chain! { - if let hir::ExprKind::MethodCall(_, [struct_calling_on, method_arg], _) = &expr.kind; - if let Some(expr_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id); - if match_def_path(cx, expr_def_id, &paths::SLICE_GET); - - if let Some(_) = is_slice_of_primitives(cx, struct_calling_on); - if let hir::ExprKind::Lit(Spanned { node: LitKind::Int(0, _), .. }) = method_arg.kind; - - then { - let mut applicability = Applicability::MachineApplicable; - let slice_name = snippet_with_applicability( - cx, - struct_calling_on.span, "..", - &mut applicability, - ); - span_lint_and_sugg( - cx, - GET_FIRST, - expr.span, - &format!("accessing first element with `{0}.get(0)`", slice_name), - "try", - format!("{}.first()", slice_name), - applicability, - ); - } - } - } -} |