a.ts(7,16): error TS2702: 'Base' only refers to a type, but is being used as a namespace here.
a.ts(13,1): error TS2309: An export assignment cannot be used in a module with other exported elements.


==== a.ts (2 errors) ====
    class Foo {}
    
    export class Base<T> {
        value!: T;
    }
    
    import _Base = Base;
                   ~~~~
!!! error TS2702: 'Base' only refers to a type, but is being used as a namespace here.
    
    namespace Foo {
        export import Base = _Base;
    }
    
    export = Foo;
    ~~~~~~~~~~~~~
!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
    
==== b.ts (0 errors) ====
    import { Base } from "./a";
    
    class Derived extends Base<string> {}