1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::source::snippet_with_applicability;
3 use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
4 use if_chain::if_chain;
5 use rustc_errors::Applicability;
6 use rustc_hir::{Expr, ExprKind, LangItem};
7 use rustc_lint::LateContext;
8 use rustc_span::symbol::sym;
10 use super::EXTEND_WITH_DRAIN;
12 pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, arg: &Expr<'_>) {
13 let ty = cx.typeck_results().expr_ty(recv).peel_refs();
15 if is_type_diagnostic_item(cx, ty, sym::Vec);
17 if let ExprKind::MethodCall(src_method, drain_vec, [drain_arg], _) = &arg.kind;
18 if src_method.ident.as_str() == "drain";
19 let src_ty = cx.typeck_results().expr_ty(drain_vec);
20 //check if actual src type is mutable for code suggestion
21 let immutable = src_ty.is_mutable_ptr();
22 let src_ty = src_ty.peel_refs();
23 if is_type_diagnostic_item(cx, src_ty, sym::Vec);
25 if let src_ty_range = cx.typeck_results().expr_ty(drain_arg).peel_refs();
26 if is_type_lang_item(cx, src_ty_range, LangItem::RangeFull);
28 let mut applicability = Applicability::MachineApplicable;
33 "use of `extend` instead of `append` for adding the full range of a second vector",
37 snippet_with_applicability(cx, recv.span, "..", &mut applicability),
38 if immutable { "" } else { "&mut " },
39 snippet_with_applicability(cx, drain_vec.span, "..", &mut applicability)