golang建立優雅的類型定義

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

package mainimport "fmt"const (    A = 1 << iota // 1 << 0 which is 00000001    B             // 1 << 1 which is 00000010    C             // 1 << 2 which is 00000100    D             // 1 << 3 which is 00001000    E             // 1 << 4 which is 00010000)func main() {    /*        print:            has A            has C            has E    */    check(A | C | E)}func check(flag int) {    if flag&A == A {        fmt.Println("has A")    }    if flag&B == B {        fmt.Println("has B")    }    if flag&C == C {        fmt.Println("has C")    }    if flag&D == D {        fmt.Println("has D")    }    if flag&E == E {        fmt.Println("has E")    }}