在go中recover之后怎么返回error

Question

package main

import (
    "fmt"
    "math"
)

func main() {
    _, err := IntFromInt64(math.MaxInt32 + 1)
    if err != nil {
        fmt.Println(err)
    }
}

func ConvertInt64ToInt(i64 int64) int {
    if math.MinInt32 <= i64 && i64 <= math.MaxInt32 {
        return int(i64)
    }
    panic("can't convert int64 to int")
}

func IntFromInt64(i64 int64) (int, error) {
    defer func() {
        if err := recover(); err != nil {
            return 0, fmt.Errorf("%v", err)
        }
    }()
    i := ConvertInt64ToInt(i64)
    return i, nil
}

defer func()中recover之后怎么返回

Answer 1

package main

import (
        "errors"
        "fmt"
        "math"
)

func main() {
        _, err := IntFromInt64(math.MaxInt32 + 1)
        if err != nil {
                fmt.Println(err)
        }
}

func ConvertInt64ToInt(i64 int64) int {
        if math.MinInt32 <= i64 && i64 <= math.MaxInt32 {
                return int(i64)
        }
        panic("can't convert int64 to int")
}

func IntFromInt64(i64 int64) (i int, err error) {//这里
        defer func() {
                if err2 := recover(); err2 != nil {
                        i = 0//这里
                        err = errors.New("ttt")//这里
                }
        }()
        i = ConvertInt64ToInt(i64)
        return i, nil
}

主要思想：return之前利用defer修改返回变量（提前确定为i和err）的值