mirror of
https://github.com/rust-lang/rust-clippy
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Refactor almost_swapped to lint with let statement correctly
This commit is contained in:
chansuke
parent
179c037643
commit
ebca1b5d00
6 changed files with 162 additions and 191 deletions
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@ -10,7 +10,7 @@ use rustc_lint::{LateContext, LateLintPass};
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use rustc_middle::ty;
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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use rustc_span::source_map::Spanned;
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use rustc_span::{sym, Span};
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use rustc_span::{sym, symbol::Ident, Span};
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declare_clippy_lint! {
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/// ### What it does
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@ -172,131 +172,78 @@ fn check_manual_swap(cx: &LateContext<'_>, block: &Block<'_>) {
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}
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}
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#[allow(clippy::too_many_lines)]
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/// Implementation of the `ALMOST_SWAPPED` lint.
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fn check_suspicious_swap(cx: &LateContext<'_>, block: &Block<'_>) {
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for w in block.stmts.windows(2) {
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if_chain! {
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if let StmtKind::Semi(first) = w[0].kind;
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if let StmtKind::Semi(second) = w[1].kind;
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if first.span.ctxt() == second.span.ctxt();
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if let ExprKind::Assign(lhs0, rhs0, _) = first.kind;
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if let ExprKind::Assign(lhs1, rhs1, _) = second.kind;
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if eq_expr_value(cx, lhs0, rhs1);
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if eq_expr_value(cx, lhs1, rhs0);
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then {
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let lhs0 = Sugg::hir_opt(cx, lhs0);
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let rhs0 = Sugg::hir_opt(cx, rhs0);
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let (what, lhs, rhs) = if let (Some(first), Some(second)) = (lhs0, rhs0) {
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(
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format!(" `{first}` and `{second}`"),
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first.mut_addr().to_string(),
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second.mut_addr().to_string(),
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)
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} else {
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(String::new(), String::new(), String::new())
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};
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let span = first.span.to(second.span);
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let Some(sugg) = std_or_core(cx) else { return };
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span_lint_and_then(cx,
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ALMOST_SWAPPED,
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span,
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&format!("this looks like you are trying to swap{what}"),
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|diag| {
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if !what.is_empty() {
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diag.span_suggestion(
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span,
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"try",
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format!(
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"{sugg}::mem::swap({lhs}, {rhs})",
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),
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Applicability::MaybeIncorrect,
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);
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diag.note(
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format!("or maybe you should use `{sugg}::mem::replace`?")
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);
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}
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});
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for [first, second] in block.stmts.array_windows() {
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if let Some((lhs0, rhs0)) = parse(first)
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&& let Some((lhs1, rhs1)) = parse(second)
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&& first.span.eq_ctxt(second.span)
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&& is_same(cx, lhs0, rhs1)
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&& is_same(cx, lhs1, rhs0)
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&& let Some(lhs_sugg) = match &lhs0 {
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ExprOrIdent::Expr(expr) => Sugg::hir_opt(cx, expr),
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ExprOrIdent::Ident(ident) => Some(Sugg::NonParen(ident.as_str().into())),
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}
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}
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let lint_almost_swapped_note = |span, what: String, sugg, lhs, rhs| {
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&& let Some(rhs_sugg) = Sugg::hir_opt(cx, rhs0)
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{
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let span = first.span.to(rhs1.span);
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let Some(sugg) = std_or_core(cx) else { return };
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span_lint_and_then(
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cx,
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ALMOST_SWAPPED,
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span,
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&format!("this looks like you are trying to swap{}", what),
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&format!("this looks like you are trying to swap `{lhs_sugg}` and `{rhs_sugg}`"),
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|diag| {
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if !what.is_empty() {
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diag.note(&format!(
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"maybe you could use `{sugg}::mem::swap({lhs}, {rhs})` or `{sugg}::mem::replace`?"
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));
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}
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diag.span_suggestion(
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span,
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"try",
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format!("{sugg}::mem::swap({}, {})", lhs_sugg.mut_addr(), rhs_sugg.mut_addr()),
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Applicability::MaybeIncorrect,
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);
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diag.note(format!("or maybe you should use `{sugg}::mem::replace`?"));
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},
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);
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};
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if let StmtKind::Local(first) = w[0].kind
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&& let StmtKind::Local(second) = w[1].kind
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&& first.span.ctxt() == second.span.ctxt()
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&& let Some(rhs0) = first.init
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&& let Some(rhs1) = second.init
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&& let ExprKind::Path(QPath::Resolved(None, path_l)) = rhs0.kind
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&& let ExprKind::Path(QPath::Resolved(None, path_r)) = rhs1.kind
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&& let PatKind::Binding(_,_, ident_l,_) = first.pat.kind
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&& let PatKind::Binding(_,_, ident_r,_) = second.pat.kind
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&& ident_l.name.as_str() == path_r.segments.iter().map(|el| el.ident.to_string()).collect::<Vec<_>>().join("::")
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&& ident_r.name.as_str() == path_l.segments.iter().map(|el| el.ident.to_string()).collect::<Vec<_>>().join("::")
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{
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let rhs0 = Sugg::hir_opt(cx, rhs0);
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let (what, lhs, rhs) = if let Some(second) = rhs0 {
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(
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format!(" `{}` and `{}`", ident_l, second),
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format!("&mut {}", ident_l),
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second.mut_addr().to_string(),
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)
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} else {
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(String::new(), String::new(), String::new())
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};
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let span = first.span.to(second.span);
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let Some(sugg) = std_or_core(cx) else { return };
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lint_almost_swapped_note(span, what, sugg, lhs, rhs);
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}
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if let StmtKind::Local(first) = w[0].kind
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&& let StmtKind::Semi(second) = w[1].kind
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&& first.span.ctxt() == second.span.ctxt()
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&& let Some(rhs0) = first.init
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&& let ExprKind::Path(QPath::Resolved(None, path_l)) = rhs0.kind
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&& let PatKind::Binding(_,_, ident_l,_) = first.pat.kind
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&& let ExprKind::Assign(lhs1, rhs1, _) = second.kind
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&& let ExprKind::Path(QPath::Resolved(None, lhs1_path)) = lhs1.kind
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&& let ExprKind::Path(QPath::Resolved(None, rhs1_path)) = rhs1.kind
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&& ident_l.name.as_str() == rhs1_path.segments.iter().map(|el| el.ident.to_string()).collect::<Vec<_>>().join("::")
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&& path_l.segments.iter().map(|el| el.ident.to_string()).collect::<Vec<_>>().join("::") == lhs1_path.segments.iter().map(|el| el.ident.to_string()).collect::<Vec<_>>().join("::")
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{
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let lhs1 = Sugg::hir_opt(cx, lhs1);
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let rhs1 = Sugg::hir_opt(cx, rhs1);
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let (what, lhs, rhs) = if let (Some(first),Some(second)) = (lhs1,rhs1) {
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(
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format!(" `{}` and `{}`", first, second),
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first.mut_addr().to_string(),
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second.mut_addr().to_string(),
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)
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} else {
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(String::new(), String::new(), String::new())
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};
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let span = first.span.to(second.span);
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let Some(sugg) = std_or_core(cx) else { return };
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lint_almost_swapped_note(span, what, sugg, lhs, rhs);
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}
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}
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}
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}
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fn is_same(cx: &LateContext<'_>, lhs: ExprOrIdent<'_>, rhs: &Expr<'_>) -> bool {
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match lhs {
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ExprOrIdent::Expr(expr) => eq_expr_value(cx, expr, rhs),
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ExprOrIdent::Ident(ident) => {
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if let ExprKind::Path(QPath::Resolved(None, path)) = rhs.kind
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&& let [segment] = &path.segments
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&& segment.ident == ident
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{
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true
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} else {
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false
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}
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}
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}
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}
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#[derive(Debug, Clone, Copy)]
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enum ExprOrIdent<'a> {
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Expr(&'a Expr<'a>),
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Ident(Ident),
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}
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fn parse<'a, 'hir>(stmt: &'a Stmt<'hir>) -> Option<(ExprOrIdent<'hir>, &'a Expr<'hir>)> {
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if let StmtKind::Semi(expr) = stmt.kind {
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if let ExprKind::Assign(lhs, rhs, _) = expr.kind {
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return Some((ExprOrIdent::Expr(lhs), rhs));
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}
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} else if let StmtKind::Local(expr) = stmt.kind {
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if let Some(rhs) = expr.init {
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if let PatKind::Binding(_, _, ident_l, _) = expr.pat.kind {
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return Some((ExprOrIdent::Ident(ident_l), rhs));
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}
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}
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}
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None
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}
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/// Implementation of the xor case for `MANUAL_SWAP` lint.
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fn check_xor_swap(cx: &LateContext<'_>, block: &Block<'_>) {
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for window in block.stmts.windows(3) {
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@ -1,32 +0,0 @@
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#![allow(clippy::needless_late_init, clippy::manual_swap)]
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#![allow(unused_variables, unused_assignments)]
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#![warn(clippy::almost_swapped)]
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fn main() {
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let b = 1;
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let a = b;
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let b = a;
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let mut c = 1;
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let mut d = 2;
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d = c;
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c = d;
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let mut b = 1;
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let a = b;
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b = a;
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let b = 1;
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let a = 2;
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let t = b;
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let b = a;
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let a = t;
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let mut b = 1;
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let mut a = 2;
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let t = b;
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b = a;
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a = t;
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}
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@ -1,30 +0,0 @@
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error: this looks like you are trying to swap `a` and `b`
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--> $DIR/almost_swapped.rs:7:5
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LL | / let a = b;
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LL | | let b = a;
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| |______________^
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= note: `-D clippy::almost-swapped` implied by `-D warnings`
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= note: maybe you could use `std::mem::swap(&mut a, &mut b)` or `std::mem::replace`?
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error: this looks like you are trying to swap `d` and `c`
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--> $DIR/almost_swapped.rs:12:5
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LL | / d = c;
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LL | | c = d;
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| |_________^ help: try: `std::mem::swap(&mut d, &mut c)`
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|
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= note: or maybe you should use `std::mem::replace`?
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error: this looks like you are trying to swap `b` and `a`
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--> $DIR/almost_swapped.rs:16:5
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LL | / let a = b;
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LL | | b = a;
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| |_________^
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= note: maybe you could use `std::mem::swap(&mut b, &mut a)` or `std::mem::replace`?
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error: aborting due to 3 previous errors
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@ -7,7 +7,8 @@
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clippy::redundant_clone,
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redundant_semicolons,
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dead_code,
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unused_assignments
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unused_assignments,
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unused_variables
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)]
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struct Foo(u32);
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@ -121,6 +122,27 @@ fn main() {
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std::mem::swap(&mut c.0, &mut a);
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; std::mem::swap(&mut c.0, &mut a);
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std::mem::swap(&mut a, &mut b);
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let mut c = 1;
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let mut d = 2;
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std::mem::swap(&mut d, &mut c);
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let mut b = 1;
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std::mem::swap(&mut a, &mut b);
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let b = 1;
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let a = 2;
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let t = b;
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let b = a;
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let a = t;
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let mut b = 1;
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let mut a = 2;
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std::mem::swap(&mut b, &mut a);
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}
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fn issue_8154() {
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@ -7,7 +7,8 @@
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clippy::redundant_clone,
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redundant_semicolons,
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dead_code,
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unused_assignments
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unused_assignments,
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unused_variables
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)]
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struct Foo(u32);
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@ -143,6 +144,32 @@ fn main() {
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; let t = c.0;
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c.0 = a;
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a = t;
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let a = b;
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let b = a;
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let mut c = 1;
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let mut d = 2;
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d = c;
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c = d;
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let mut b = 1;
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let a = b;
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b = a;
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let b = 1;
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let a = 2;
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let t = b;
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let b = a;
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let a = t;
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let mut b = 1;
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let mut a = 2;
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let t = b;
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b = a;
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a = t;
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}
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fn issue_8154() {
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|
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@ -1,5 +1,5 @@
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error: this looks like you are swapping `bar.a` and `bar.b` manually
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--> $DIR/swap.rs:24:5
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--> $DIR/swap.rs:25:5
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LL | / let temp = bar.a;
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LL | | bar.a = bar.b;
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@ -10,7 +10,7 @@ LL | | bar.b = temp;
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= note: `-D clippy::manual-swap` implied by `-D warnings`
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error: this looks like you are swapping elements of `foo` manually
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--> $DIR/swap.rs:36:5
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--> $DIR/swap.rs:37:5
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|
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LL | / let temp = foo[0];
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LL | | foo[0] = foo[1];
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@ -18,7 +18,7 @@ LL | | foo[1] = temp;
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| |_________________^ help: try: `foo.swap(0, 1)`
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error: this looks like you are swapping elements of `foo` manually
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--> $DIR/swap.rs:45:5
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--> $DIR/swap.rs:46:5
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|
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LL | / let temp = foo[0];
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LL | | foo[0] = foo[1];
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@ -26,7 +26,7 @@ LL | | foo[1] = temp;
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| |_________________^ help: try: `foo.swap(0, 1)`
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error: this looks like you are swapping elements of `foo` manually
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--> $DIR/swap.rs:64:5
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--> $DIR/swap.rs:65:5
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|
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LL | / let temp = foo[0];
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LL | | foo[0] = foo[1];
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@ -34,7 +34,7 @@ LL | | foo[1] = temp;
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| |_________________^ help: try: `foo.swap(0, 1)`
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error: this looks like you are swapping `a` and `b` manually
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--> $DIR/swap.rs:75:5
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--> $DIR/swap.rs:76:5
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|
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LL | / a ^= b;
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LL | | b ^= a;
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@ -42,7 +42,7 @@ LL | | a ^= b;
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| |___________^ help: try: `std::mem::swap(&mut a, &mut b)`
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error: this looks like you are swapping `bar.a` and `bar.b` manually
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--> $DIR/swap.rs:83:5
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--> $DIR/swap.rs:84:5
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|
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LL | / bar.a ^= bar.b;
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LL | | bar.b ^= bar.a;
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@ -50,7 +50,7 @@ LL | | bar.a ^= bar.b;
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| |___________________^ help: try: `std::mem::swap(&mut bar.a, &mut bar.b)`
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error: this looks like you are swapping elements of `foo` manually
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--> $DIR/swap.rs:91:5
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--> $DIR/swap.rs:92:5
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|
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LL | / foo[0] ^= foo[1];
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LL | | foo[1] ^= foo[0];
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@ -58,7 +58,7 @@ LL | | foo[0] ^= foo[1];
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| |_____________________^ help: try: `foo.swap(0, 1)`
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error: this looks like you are swapping `foo[0][1]` and `bar[1][0]` manually
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--> $DIR/swap.rs:120:5
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--> $DIR/swap.rs:121:5
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|
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LL | / let temp = foo[0][1];
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LL | | foo[0][1] = bar[1][0];
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|
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@ -68,7 +68,7 @@ LL | | bar[1][0] = temp;
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= note: or maybe you should use `std::mem::replace`?
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error: this looks like you are swapping `a` and `b` manually
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--> $DIR/swap.rs:134:7
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--> $DIR/swap.rs:135:7
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|
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LL | ; let t = a;
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| _______^
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|
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@ -79,7 +79,7 @@ LL | | b = t;
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= note: or maybe you should use `std::mem::replace`?
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error: this looks like you are swapping `c.0` and `a` manually
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--> $DIR/swap.rs:143:7
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--> $DIR/swap.rs:144:7
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|
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LL | ; let t = c.0;
|
||||
| _______^
|
||||
|
|
@ -89,8 +89,18 @@ LL | | a = t;
|
|||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are swapping `b` and `a` manually
|
||||
--> $DIR/swap.rs:170:5
|
||||
|
|
||||
LL | / let t = b;
|
||||
LL | | b = a;
|
||||
LL | | a = t;
|
||||
| |_________^ help: try: `std::mem::swap(&mut b, &mut a)`
|
||||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are trying to swap `a` and `b`
|
||||
--> $DIR/swap.rs:131:5
|
||||
--> $DIR/swap.rs:132:5
|
||||
|
|
||||
LL | / a = b;
|
||||
LL | | b = a;
|
||||
|
|
@ -100,7 +110,7 @@ LL | | b = a;
|
|||
= note: `-D clippy::almost-swapped` implied by `-D warnings`
|
||||
|
||||
error: this looks like you are trying to swap `c.0` and `a`
|
||||
--> $DIR/swap.rs:140:5
|
||||
--> $DIR/swap.rs:141:5
|
||||
|
|
||||
LL | / c.0 = a;
|
||||
LL | | a = c.0;
|
||||
|
|
@ -108,8 +118,35 @@ LL | | a = c.0;
|
|||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are trying to swap `a` and `b`
|
||||
--> $DIR/swap.rs:148:5
|
||||
|
|
||||
LL | / let a = b;
|
||||
LL | | let b = a;
|
||||
| |_____________^ help: try: `std::mem::swap(&mut a, &mut b)`
|
||||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are trying to swap `d` and `c`
|
||||
--> $DIR/swap.rs:153:5
|
||||
|
|
||||
LL | / d = c;
|
||||
LL | | c = d;
|
||||
| |_________^ help: try: `std::mem::swap(&mut d, &mut c)`
|
||||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are trying to swap `a` and `b`
|
||||
--> $DIR/swap.rs:157:5
|
||||
|
|
||||
LL | / let a = b;
|
||||
LL | | b = a;
|
||||
| |_________^ help: try: `std::mem::swap(&mut a, &mut b)`
|
||||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: this looks like you are swapping `s.0.x` and `s.0.y` manually
|
||||
--> $DIR/swap.rs:178:5
|
||||
--> $DIR/swap.rs:205:5
|
||||
|
|
||||
LL | / let t = s.0.x;
|
||||
LL | | s.0.x = s.0.y;
|
||||
|
|
@ -118,5 +155,5 @@ LL | | s.0.y = t;
|
|||
|
|
||||
= note: or maybe you should use `std::mem::replace`?
|
||||
|
||||
error: aborting due to 13 previous errors
|
||||
error: aborting due to 17 previous errors
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue