package main
import "runtime"
// go run -ldflags "-X main.minGoVersion=go1.5.1" main.go
// 参考自 http://stackoverflow.com/questions/18409373/how-to-compare-two-version-number-strings-in-golang
func VersionOrdinal(version string) string {
    // ISO/IEC 14651:2011
    const maxByte = 1<<8 - 1
    vo := make([]byte, 0, len(version)+8)
    j := -1
    for i := 0; i < len(version); i++ {
        b := version[i]
        if '0' > b || b > '9' {
            vo = append(vo, b)
            j = -1
            continue
        }
        if j == -1 {
            vo = append(vo, 0x00)
            j = len(vo) - 1
        }
        if vo[j] == 1 && vo[j+1] == '0' {
            vo[j+1] = b
            continue
        }
        if vo[j]+1 > maxByte {
            panic("VersionOrdinal: invalid version")
        }
        vo = append(vo, b)
        vo[j]++
    }
    return string(vo)
}
var minGoVersion string
func init() {
    if minGoVersion == "" {
        panic("请传递 -ldflags \"-X main.minGoVersion=<version string>\" 参数")
    }
    current := VersionOrdinal(runtime.Version())
    desired := VersionOrdinal(minGoVersion)
    if current < desired {
        panic("不支持的Go语言运行时版本 " + current + " < " + desired)
    }
}
func main() {
}