decoratorOnClassConstructorParameter1.ts(4,18): error TS1239: Unable to resolve signature of parameter decorator when called as an expression.
  Argument of type 'undefined' is not assignable to parameter of type 'string | symbol'.


==== decoratorOnClassConstructorParameter1.ts (1 errors) ====
    declare function dec(target: Function, propertyKey: string | symbol, parameterIndex: number): void;
    
    class C {
        constructor(@dec p: number) {}
                     ~~~
!!! error TS1239: Unable to resolve signature of parameter decorator when called as an expression.
!!! error TS1239:   Argument of type 'undefined' is not assignable to parameter of type 'string | symbol'.
    }