Go语言基本类型接口与泛型数值处理：Type Switch与反射机制解析

package main

import (
    "fmt"
    "reflect" // 用于panic信息，非核心逻辑
)

func squareWithTypeSwitch(num interface{}) interface{} {
    switch x := num.(type) {
    case int:
        return x * x
    case int8:
        return x * x
    case int16:
        return x * x
    case int32:
        return x * x
    case int64:
        return x * x
    case uint:
        return x * x
    case uint8:
        return x * x
    case uint16:
        return x * x
    case uint32:
        return x * x
    case uint64:
        return x * x
    case float32:
        return x * x
    case float64:
        return x * x
    // 如果需要支持更多数值类型，如complex64/128，需继续添加case
    default:
        panic(fmt.Sprintf("squareWithTypeSwitch(): 不支持的类型 %s", reflect.TypeOf(num).Name()))
    }
}

func main() {
    fmt.Println("--- Type Switch 示例 ---")
    fmt.Printf("square(5) = %v (类型: %T)\n", squareWithTypeSwitch(5), squareWithTypeSwitch(5))
    fmt.Printf("square(5.0) = %v (类型: %T)\n", squareWithTypeSwitch(5.0), squareWithTypeSwitch(5.0))
    fmt.Printf("square(uint(3)) = %v (类型: %T)\n", squareWithTypeSwitch(uint(3)), squareWithTypeSwitch(uint(3)))
    // 尝试传递不支持的类型会引发panic
    // fmt.Printf("square(\"hello\") = %v\n", squareWithTypeSwitch("hello"))
}

package main

import (
    "fmt"
    "reflect"
)

func squareWithReflect(num interface{}) interface{} {
    v := reflect.ValueOf(num)
    // 创建一个与原始类型相同的新值，用于存储结果
    // reflect.New(v.Type()) 创建一个指向新值的指针
    // reflect.Indirect() 解引用，得到可设置的reflect.Value
    ret := reflect.Indirect(reflect.New(v.Type()))

    switch v.Type().Kind() {
    case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
        x := v.Int()
        ret.SetInt(x * x)
    case reflect.Uint, reflect.Uintptr, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
        x := v.Uint()
        ret.SetUint(x * x)
    case reflect.Float32, reflect.Float64:
        x := v.Float()
        ret.SetFloat(x * x)
    default:
        panic(fmt.Sprintf("squareWithReflect(): 不支持的类型 %s", v.Type().Name()))
    }

    return ret.Interface() // 将reflect.Value转换回interface{}
}

func main() {
    fmt.Println("\n--- Reflect 示例 ---")
    fmt.Printf("square(5) = %v (类型: %T)\n", squareWithReflect(5), squareWithReflect(5))
    fmt.Printf("square(5.0) = %v (类型: %T)\n", squareWithReflect(5.0), squareWithReflect(5.0))
    fmt.Printf("square(uint(3)) = %v (类型: %T)\n", squareWithReflect(uint(3)), squareWithReflect(uint(3)))
}