import { Equals } from './equals';
/**
 * 获取readonly的类型
 * @example
 * 输入：
 * type Example = { readonly foo: string; bar: number };
 * type example = ReadonlyKeys<Example>
 * 输出：
 * type example = {
 *   readonly foo: string;
 *}
 */
export type ReadonlyKeys<T> = Pick<T, {
    [K in keyof T]: Equals<{
        [O in K]: T[K];
    }, {
        -readonly [O in K]: T[K];
    }, never, K>;
}[keyof T]>;