我认为我误解了 Go 多态性/接口/结构

Question

我不明白为什么下面的代码不能编译。

我很困惑为什么 Go 说HistoryReader没有正确实现IReader。HistoryBook实现IBook. 当尝试将 a 添加到 s 的切片时，为什么Read(book Ibook)和不能同时接受？Read(book HistoryBook)HistoryReaderIReader

package main

type IReader interface {
   Read(book IBook)
}

// HistoryReader implements IReader
type HistoryReader struct{}

func (r *HistoryReader) Read(book HistoryBook) {
   // ...
}

type IBook interface{}

// HistoryBook implements IBook
type HistoryBook struct{}

func main() {
   var readerSlice []IReader

   _ = append(readerSlice, &HistoryReader{})
}

package main

type IReader interface {
   Read(book IBook)
}

// HistoryReader implements IReader
type HistoryReader struct{}

func (r *HistoryReader) Read(book HistoryBook) {
   // ...
}

type IBook interface{}

// HistoryBook implements IBook
type HistoryBook struct{}

func main() {
   var readerSlice []IReader

   _ = append(readerSlice, &HistoryReader{})
}

Answer 1

IReader要求Read需要任何IBook.

但HistoryReader.Read只接受一个HistoryBook，不接受任何IBook。因此，HistoryReader不满足IReader.