有没有一种方法可以使用地图和界面在Go中的不同包中转换结构？

I want to convert some struct types between different packages and then operate on the structs that are in my package without using if/else or switch statements. Is that possible to do using just maps and interfaces? I have some ideas in place for how I can do this.

Package Other

type Update interface{}

type FirstUpdate struct {
    x int
    y int
}

type SecondUpdate struct {
    z string
}

// these methods return different implementations of Update structs
FirstRequestConverter(events []string, topic string) Update
SecondRequestConverter(events []string, topic string) Update

Package Mine

type ConversionFunction func([]string, string) other.Update

type FirstUpdateConverted other.FirstUpdate
type SecondUpdateConverted other.SecondUpdate

type ServiceCaller interface {
    // includes relevant methods
}    

topicsMap := map[string]ConversionFunction{
    "first_topic": other.FirstRequestConverter,
    "second_topic": other.SecondRequestConverter,
}

conversionFunction = topicsMap[topic]
// need to convert other package types to alias types
...
updateConverted.callService()

Here, my map from string to ConversionFunction lets me pick the conversion function I want to use at runtime. And if both FirstUpdateConverted and SecondUpdateConverted implement the ServiceCaller interface, I can choose how the converted structure is handled at runtime too.

In order to convert from FirstUpdate to FirstUpdateConverted (or any of the other alias types), however, I need to use a switch and convert manually.

Is there another way to do the struct conversion step?