有一个使用泛型的简单示例，我们希望在其中复制Map

package main

import "fmt"

type myMap interface {
    map[string]int | map[string]float64
}

func copyMap[T myMap](m T) T {
    newMap := make(T)
    for key, elem := range m {
        newMap[key] = elem
    }

    return newMap
}

func main() {
    m := map[string]int{"seven": 7}
    fmt.Println(copyMap(m))
}

演示here
此代码编译失败，返回错误

./prog.go:12:17: invalid argument: cannot make T: no core type
./prog.go:13:25: cannot range over m (variable of type T constrained by myMap) (T has no core type)
./prog.go:14:18: invalid operation: cannot index m (variable of type T constrained by myMap)

我怎样才能避免这个问题，并让一个通用的copyMap函数适用于map[string]int和map[string]float64类型呢？