go中如果想要实现别人写的接口,如何保证确实实现了那个接口而不是错过了什么?

在类型的实现方法上定义通用代码指令

var _ 要实现的接口  = (receiver类型)(nil)

 

 

比如要定义一个web处理程序

type  handler_def struct{}

 

var _ http.Handler = (*handler_def)(nil)    //(*handler_def)(nil)   构建指针/切片/map的零值

func (h *handler_def)ServeHTTP(参数){}

 

当你编译go build xxxx.go

报错参考如下,可以看到很清楚的解释.

?

1 2 3 4 5

# command-line-arguments .\main.go:9:5: cannot use (*Handler)(nil) (type *Handler) as type http.Handler in assignment:         *Handler does not implement http.Handler (wrong type for ServeHTTP method)                 have ServeHTTP(http.ResponseWriter, http.Request)                 want ServeHTTP(http.ResponseWriter, *http.Request)