example.go

// example6.go
package main

import "fmt"

type Number interface {
	int64 | float64
}

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,
	}

	fmt.Printf("Non-Generic Sums: %v and %v\n",
		SumInts(ints),
		SumFloats(floats))

	fmt.Printf("Generic Sums: %v and %v\n",
		SumIntsOrFloats[string, int64](ints),
		SumIntsOrFloats[string, float64](floats))

	fmt.Printf("Generic Sums, type parameters inferred: %v and %v\n",
		SumIntsOrFloats(ints),
		SumIntsOrFloats(floats))

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

// SumInts adds together the values of m.
func SumInts(m map[string]int64) int64 {
	var s int64
	for _, v := range m {
		s += v
	}
	return s
}

// SumFloats adds together the values of m.
func SumFloats(m map[string]float64) float64 {
	var s float64
	for _, v := range m {
		s += v
	}
	return s
}

// SumIntsOrFloats sums the values of map m. It supports both floats and integers
// as map values.
func SumIntsOrFloats[K comparable, V int64 | float64](m map[K]V) V {
var s V
for _, v := range m {
s += v
}
return s
}

// 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
}