spread types may only be created from code example

Example 1: spread types may only be created from

function foo<T extends object>(t: T): T {
  return { ...(t as object) } as T;
}

Example 2: spread types may only be created from

function foo<T extends object>(t: T): T {

  return {
    ...t    // Error: [ts] Spread types may only be created from object types.
  }
}