class I<SS extends string>{
    f() {
        let x: [ //Errors when SS is generic and `t` exists
            t: "AAA",
            ...args: {
                [S in SS]: [a: number];
            }[SS]
        ] = ["AAA", 1];

        type SS1 = string;
        let y: [ // OK when SS1 is not generic
            t: "AAA",
            ...args: {
                [S in SS1]: [a: number];
            }[SS1]
        ] = ["AAA", 1];

        type SS2 = "1" | "2" | "3";
        let z: [ // OK when SS2 is not generic
            t: "AAA",
            ...args: {
                [S in SS2]: [a: number];
            }[SS2]
        ] = ["AAA", 1];

        let w: [ // OK when `t` doesn't exist!!!
            ...args: {
                [S in SS]: [a: number];
            }[SS]
        ] = [1];
    }
}