my_generics.go

package main

import (
	"constraints"
	"fmt"
)

type Number interface {
	constraints.Integer | constraints.Float | constraints.Complex
}

func main() {
	// Initialize a map for the integer values
	ints := map[string]int64{
		"first":  34,
		"second": 12,
	}

	// Initialize a map for the float values
	floats := map[string]float64{
		"first":  35.98,
		"second": 26.99,
	}

	// Initialize a map for the complex values
	complexes := map[string]complex128{
		"first":  23 + 45i,
		"second": 12 + 34i,
	}

	fmt.Printf("Generic Sums with Constraint: %v and %v and %v\n",
		SumNumbers(ints),
		SumNumbers(floats),
		SumNumbers(complexes))
}

// SumNumbers sums the values of map m. Its supports both integers
// and floats as map values.
func SumNumbers[K comparable, V Number](m map[K]V) V {
	var s V
	for _, v := range m {
		s += v
	}
	return s
}

Taking https://go.dev/doc/tutorial/generics on a little with constraints and complex numbers