tests/cases/compiler/doNotElaborateAssignabilityToTypeParameters.ts(3,3): error TS2322: Type 'T | Yadda' is not assignable to type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'T | Yadda'.


==== tests/cases/compiler/doNotElaborateAssignabilityToTypeParameters.ts (1 errors) ====
    async function foo<T>(x: T): Promise<T> {
      let yaddable = await getXOrYadda(x);
      return yaddable;
      ~~~~~~~~~~~~~~~~
!!! error TS2322: Type 'T | Yadda' is not assignable to type 'T'.
!!! error TS2322:   'T' could be instantiated with an arbitrary type which could be unrelated to 'T | Yadda'.
    }
    
    interface Yadda {
      stuff: string,
      things: string,
    }
    
    declare function getXOrYadda<T>(x: T): T | Yadda;
    