rust/tests/ui/author/matches.stdout

if let StmtKind::Let(local) = stmt.kind
    && let Some(init) = local.init
    && let ExprKind::Match(scrutinee, arms, MatchSource::Normal) = init.kind
    && let ExprKind::Lit(ref lit) = scrutinee.kind
    && let LitKind::Int(42, LitIntType::Unsuffixed) = lit.node
    && arms.len() == 3
    && let PatKind::Lit(lit_expr) = arms[0].pat.kind
    && let ExprKind::Lit(ref lit1) = lit_expr.kind
    && let LitKind::Int(16, LitIntType::Unsuffixed) = lit1.node
    && arms[0].guard.is_none()
    && let ExprKind::Lit(ref lit2) = arms[0].body.kind
    && let LitKind::Int(5, LitIntType::Unsuffixed) = lit2.node
    && let PatKind::Lit(lit_expr1) = arms[1].pat.kind
    && let ExprKind::Lit(ref lit3) = lit_expr1.kind
    && let LitKind::Int(17, LitIntType::Unsuffixed) = lit3.node
    && arms[1].guard.is_none()
    && let ExprKind::Block(block, None) = arms[1].body.kind
    && block.stmts.len() == 1
    && let StmtKind::Let(local1) = block.stmts[0].kind
    && let Some(init1) = local1.init
    && let ExprKind::Lit(ref lit4) = init1.kind
    && let LitKind::Int(3, LitIntType::Unsuffixed) = lit4.node
    && let PatKind::Binding(BindingMode::NONE, _, name, None) = local1.pat.kind
    && name.as_str() == "x"
    && let Some(trailing_expr) = block.expr
    && let ExprKind::Path(ref qpath) = trailing_expr.kind
    && match_qpath(qpath, &["x"])
    && let PatKind::Wild = arms[2].pat.kind
    && arms[2].guard.is_none()
    && let ExprKind::Lit(ref lit5) = arms[2].body.kind
    && let LitKind::Int(1, LitIntType::Unsuffixed) = lit5.node
    && let PatKind::Binding(BindingMode::NONE, _, name1, None) = local.pat.kind
    && name1.as_str() == "a"
{
    // report your lint here
}