Go中函数变量的类型

Question

I want to write a function which takes a pointer to any type of function. I could do:

func myFunc(f interface{})

...but that would allow non-function values. Is there any way I can restrict the type to any function?

Answer 1

Assuming you literally mean any function, you can either do a type switch (which would be specific):

switch v.(type) {
case func() int:
case func() string:
}

Or you could use the reflect package to determine the type:

if reflect.TypeOf(v).Kind() != reflect.Func {
    // error here
}

This is a runtime solution. Other than that, there's nothing else you can do. The downside about this is the compiler won't stop someone from passing a non-function value.

Personally I would avoid doing this, and I would expect a specific func prototype, like:

func myFunc(f func() string)

With this you're less likely to have errors when the compiler knows what the types are.