Typescript 在MessageStore对象中实现条件类型时出现TypeScrip错误

我在MessagesStore对象中实现条件类型时遇到打字错误.以下是完整的代码设置:

type Message = { id: number; text: string };

type MessagesStore = {
    queue: Array<Message>;
    read: <T extends boolean>(assertiveMode?: T) => T extends true ? Message : Message | undefined;
}

const store: MessagesStore = {
    queue: [],

    read(assertiveMode: boolean = false) {
        const message = this.queue.shift();

        if (assertiveMode && message === undefined) {
            throw new Error('The messages queue is empty');
        }

        return message;
    }
}

但是，TypeScrip会引发以下错误:

Type '<T extends boolean>(assertiveMode?: boolean) => Message | undefined' is not assignable to type '<T extends boolean>(assertiveMode?: T | undefined) => T extends true ? Message : Message | undefined'.
  Type 'Message | undefined' is not assignable to type 'T extends true ? Message : Message | undefined'.
    Type 'undefined' is not assignable to type 'T extends true ? Message : Message | undefined'.

我很难理解为什么我会收到这个错误，以及如何解决它.