TS2538：类型“唯一符号”不能用作索引类型

Question

我有这个：

const symbols = {
   typeMap: Symbol('type.map')
}

interface LangMap {
  [key: string]: string | true,
  golang: string,
  typescript: string,
  java: string,
  swift: string
}

export const setTypeMap = function(v: LangMap) : LangMap{
  v[symbols.typeMap] = true;
  return v;
};

我收到此错误：

TS2538：类型“唯一符号”不能用作索引类型。

有人知道这个错误是什么意思吗？我使用的是 tsc 版本3.1.6。

Answer 1

这有效：

type SymbolObject<T extends object = Record<any,any>, K = T[keyof T]> = {
[key:string|number|symbol]:K
}
// it would be advised to have true type definitions here, but that's annoying.
const bar:SymbolObject = {};
const foo = Symbol("foo");
bar[foo] = "hello!"

Answer 2

我糟糕的解决方法：

const bar: Record<any, string> = {};
const FOO = Symbol('foo');

// eslint-disable-next-line @typescript-eslint/no-explicit-any
bar[FOO as any] = 'sad';