use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::{snippet, snippet_with_macro_callsite};
use clippy_utils::sugg::Sugg;
-use clippy_utils::ty::is_type_diagnostic_item;
-use clippy_utils::{get_parent_expr, match_def_path, match_trait_method, paths};
+use clippy_utils::ty::{is_type_diagnostic_item, same_type_and_consts};
+use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, paths};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, HirId, MatchSource};
use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{self, TyS};
+use rustc_middle::ty;
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::sym;
declare_clippy_lint! {
- /// **What it does:** Checks for `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` calls
+ /// ### What it does
+ /// Checks for `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` calls
/// which uselessly convert to the same type.
///
- /// **Why is this bad?** Redundant code.
- ///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Why is this bad?
+ /// Redundant code.
///
+ /// ### Example
/// ```rust
- /// // Bad
/// // format!() returns a `String`
/// let s: String = format!("hello").into();
+ /// ```
///
- /// // Good
+ /// Use instead:
+ /// ```rust
/// let s: String = format!("hello");
/// ```
+ #[clippy::version = "1.45.0"]
pub USELESS_CONVERSION,
complexity,
"calls to `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` which perform useless conversions to the same type"
impl_lint_pass!(UselessConversion => [USELESS_CONVERSION]);
-#[allow(clippy::too_many_lines)]
+#[expect(clippy::too_many_lines)]
impl<'tcx> LateLintPass<'tcx> for UselessConversion {
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
if e.span.from_expansion() {
},
ExprKind::MethodCall(name, .., args, _) => {
- if match_trait_method(cx, e, &paths::INTO) && &*name.ident.as_str() == "into" {
+ if is_trait_method(cx, e, sym::Into) && name.ident.as_str() == "into" {
let a = cx.typeck_results().expr_ty(e);
let b = cx.typeck_results().expr_ty(&args[0]);
- if TyS::same_type(a, b) {
+ if same_type_and_consts(a, b) {
let sugg = snippet_with_macro_callsite(cx, args[0].span, "<expr>").to_string();
span_lint_and_sugg(
cx,
);
}
}
- if match_trait_method(cx, e, &paths::INTO_ITERATOR) && name.ident.name == sym::into_iter {
+ if is_trait_method(cx, e, sym::IntoIterator) && name.ident.name == sym::into_iter {
if let Some(parent_expr) = get_parent_expr(cx, e) {
if let ExprKind::MethodCall(parent_name, ..) = parent_expr.kind {
if parent_name.ident.name != sym::into_iter {
}
let a = cx.typeck_results().expr_ty(e);
let b = cx.typeck_results().expr_ty(&args[0]);
- if TyS::same_type(a, b) {
+ if same_type_and_consts(a, b) {
let sugg = snippet(cx, args[0].span, "<expr>").into_owned();
span_lint_and_sugg(
cx,
}
}
if_chain! {
- if match_trait_method(cx, e, &paths::TRY_INTO_TRAIT) && &*name.ident.as_str() == "try_into";
+ if is_trait_method(cx, e, sym::TryInto) && name.ident.name == sym::try_into;
let a = cx.typeck_results().expr_ty(e);
let b = cx.typeck_results().expr_ty(&args[0]);
- if is_type_diagnostic_item(cx, a, sym::result_type);
+ if is_type_diagnostic_item(cx, a, sym::Result);
if let ty::Adt(_, substs) = a.kind();
if let Some(a_type) = substs.types().next();
- if TyS::same_type(a_type, b);
+ if same_type_and_consts(a_type, b);
+
then {
span_lint_and_help(
cx,
let b = cx.typeck_results().expr_ty(&args[0]);
if_chain! {
if match_def_path(cx, def_id, &paths::TRY_FROM);
- if is_type_diagnostic_item(cx, a, sym::result_type);
+ if is_type_diagnostic_item(cx, a, sym::Result);
if let ty::Adt(_, substs) = a.kind();
if let Some(a_type) = substs.types().next();
- if TyS::same_type(a_type, b);
+ if same_type_and_consts(a_type, b);
then {
let hint = format!("consider removing `{}()`", snippet(cx, path.span, "TryFrom::try_from"));
if_chain! {
if match_def_path(cx, def_id, &paths::FROM_FROM);
- if TyS::same_type(a, b);
+ if same_type_and_consts(a, b);
then {
let sugg = Sugg::hir_with_macro_callsite(cx, &args[0], "<expr>").maybe_par();