"io"
	"os"
	"strconv"
)

func listGroupsFromReader(u *User, r io.Reader) ([]string, error) {
	if u.Username == "" {
		return nil, errors.New("user: list groups: empty username")
	}
	primaryGid, err := strconv.Atoi(u.Gid)
	if err != nil {
		return nil, fmt.Errorf("user: list groups for %s: invalid gid %q", u.Username, u.Gid)
	}

	userCommas := []byte("," + u.Username + ",")  // ,john,

// Package strconv implements conversions to and from string representations
// of basic data types.
//
// # Numeric Conversions
//
// The most common numeric conversions are [Atoi] (string to int) and [Itoa] (int to string).
//
//	i, err := strconv.Atoi("-42")
//	s := strconv.Itoa(-42)
//
// These assume decimal and the Go int type.
//
// [ParseBool], [ParseFloat], [ParseInt], and [ParseUint] convert strings to values:
//

	}

	matches := goVersionRE.FindStringSubmatch(s)
	if matches == nil {
		return lang{}, fmt.Errorf(`should be something like "go1.12"`)
	}
	major, err := strconv.Atoi(matches[1])
	if err != nil {
		return lang{}, err
	}
	minor, err := strconv.Atoi(matches[2])
	if err != nil {
		return lang{}, err
	}
	return lang{major: major, minor: minor}, nil
}

// currentLang returns the current language version.

			if err != nil {
				return fmt.Errorf("failed to find 'lo' link: %v", err)
			}
			tproxyTable, err := strconv.Atoi(cfg.InboundTProxyRouteTable)
			if err != nil {
				return fmt.Errorf("failed to parse InboundTProxyRouteTable: %v", err)
			}
			tproxyMark, err := strconv.Atoi(cfg.InboundTProxyMark)
			if err != nil {
				return fmt.Errorf("failed to parse InboundTProxyMark: %v", err)
			}

		if len(parts) < 6 || parts[idx] != value || parts[0] == "" ||
			parts[0][0] == '+' || parts[0][0] == '-' {
			return
		}
		if _, err := strconv.Atoi(parts[2]); err != nil {
			return nil, nil
		}
		if _, err := strconv.Atoi(parts[3]); err != nil {
			return nil, nil
		}
		u := &User{
			Username: parts[0],
			Uid:      parts[2],
			Gid:      parts[3],
			Name:     parts[4],

	fn1 := func() int {
		var i interface{} = v
		val := fn(i.(T))
		return val
	}
	return fn1()
}

func main() {
	want := 123
	got := test1(func(s string) int {
		r, err := strconv.Atoi(s)
		if err != nil {
			return 0
		}
		return r
	}, "123")
	if got != want {
		panic(fmt.Sprintf("got %f, want %f", got, want))
	}

func majmin() (major int, minor int, err error) {
	var v Utsname
	err = Uname(&v)
	if err != nil {
		return
	}

	major, err = strconv.Atoi(string(v.Release[0]))
	if err != nil {
		err = errors.New("cannot parse major version number returned by uname")
		return
	}

	minor, err = strconv.Atoi(string(v.Release[2]))
	if err != nil {
		err = errors.New("cannot parse minor version number returned by uname")
		return
	}

	return

		queueSize, err := strconv.Atoi(queueSizeCfgVal)
		if err != nil {
			return cfg, err
		}
		if queueSize <= 0 {
			return cfg, errInvalidQueueSize
		}
		batchSizeCfgVal := getCfgVal(EnvLoggerWebhookBatchSize, k, kv.Get(BatchSize))
		batchSize, err := strconv.Atoi(batchSizeCfgVal)
		if err != nil {
			return cfg, err
		}
		if batchSize <= 0 {

	if err != nil {
		return -1
	}
	v, err := strconv.Atoi(clusterVersion.Major + clusterVersion.Minor)
	if err != nil {
		// Apparently some clusters don't put proper numbers here. Try GitVersion
		vp, err := version.ParseGeneric(clusterVersion.GitVersion)
		if err != nil {
			// no good
			return -1
		}
		np, err := strconv.Atoi(fmt.Sprintf("%d%d", vp.Major(), vp.Minor()))
		if err != nil {
			// no good...

			if ifi == nil || name == ifi.Name {
				// The Linux kernel puts the IP
				// address in /proc/net/igmp in native
				// endianness.
				for i := 0; i+1 < len(f[0]); i += 2 {
					b[i/2], _ = xtoi2(f[0][i:i+2], 0)
				}
				i := *(*uint32)(unsafe.Pointer(&b[:4][0]))
				ifma := &IPAddr{IP: IPv4(byte(i>>24), byte(i>>16), byte(i>>8), byte(i))}
				ifmat = append(ifmat, ifma)
			}
		}
	}
	return ifmat