【Go官方文档】Getting started with generics

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go mod init example/generics

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package main

import "fmt"

// 定义约束
type Number interface {
	int64 | float64
}

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

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("Generic Sums: %v and %v\n",
		SumNumbers(ints),
		SumNumbers(floats))
}

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go run .

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Generic Sums: 46 and 62.97