PRINT-DERIVE INPUT (DISPLAY): struct Foo
{
    val :
    [bool ;
     {
         let a = #[rustc_dummy(first)] #[rustc_dummy(second)]
         { # ! [allow(unused)] 30 } ; 0
     }],
}
PRINT-DERIVE INPUT (DEBUG): TokenStream [
    Ident {
        ident: "struct",
        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
    },
    Ident {
        ident: "Foo",
        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
    },
    Group {
        delimiter: Brace,
        stream: TokenStream [
            Ident {
                ident: "val",
                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
            },
            Punct {
                ch: ':',
                spacing: Alone,
                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
            },
            Group {
                delimiter: Bracket,
                stream: TokenStream [
                    Ident {
                        ident: "bool",
                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                    },
                    Punct {
                        ch: ';',
                        spacing: Alone,
                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                    },
                    Group {
                        delimiter: Brace,
                        stream: TokenStream [
                            Ident {
                                ident: "let",
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Ident {
                                ident: "a",
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Punct {
                                ch: '=',
                                spacing: Alone,
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Punct {
                                ch: '#',
                                spacing: Alone,
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Group {
                                delimiter: Bracket,
                                stream: TokenStream [
                                    Ident {
                                        ident: "rustc_dummy",
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                    Group {
                                        delimiter: Parenthesis,
                                        stream: TokenStream [
                                            Ident {
                                                ident: "first",
                                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                            },
                                        ],
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                ],
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Punct {
                                ch: '#',
                                spacing: Alone,
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Group {
                                delimiter: Bracket,
                                stream: TokenStream [
                                    Ident {
                                        ident: "rustc_dummy",
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                    Group {
                                        delimiter: Parenthesis,
                                        stream: TokenStream [
                                            Ident {
                                                ident: "second",
                                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                            },
                                        ],
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                ],
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Group {
                                delimiter: Brace,
                                stream: TokenStream [
                                    Punct {
                                        ch: '#',
                                        spacing: Joint,
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                    Punct {
                                        ch: '!',
                                        spacing: Alone,
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                    Group {
                                        delimiter: Bracket,
                                        stream: TokenStream [
                                            Ident {
                                                ident: "allow",
                                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                            },
                                            Group {
                                                delimiter: Parenthesis,
                                                stream: TokenStream [
                                                    Ident {
                                                        ident: "unused",
                                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                                    },
                                                ],
                                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                            },
                                        ],
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                    Literal {
                                        kind: Integer,
                                        symbol: "30",
                                        suffix: None,
                                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                                    },
                                ],
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Punct {
                                ch: ';',
                                spacing: Alone,
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                            Literal {
                                kind: Integer,
                                symbol: "0",
                                suffix: None,
                                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                            },
                        ],
                        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
                    },
                ],
                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
            },
            Punct {
                ch: ',',
                spacing: Alone,
                span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
            },
        ],
        span: $DIR/macro-rules-derive-cfg.rs:17:9: 22:10 (#4),
    },
]