drxrgundk062317205 2018-09-03 12:50
浏览 653
已采纳

如何在Golang中初始化接口数组?

I want to initialize a map containing a list of interface without having to add them one by one:

type Pixel struct {
    X float64
    Y float64
}

type Vertex struct {
    X float64
    Y float64
    Z float64
}
type testpair struct {
    filename       string
    values     []interface{}
}
var tests = map[string]testpair{
   "test1": {
               filename: "file1.csv",
               values:  []Pixel{
                           {X: 12.5, Y: 23.4},
                           {X: 17.2, Y: 7.9},
                      }
            },
   "test2": {
               filename: "file2.csv",
               values:  []Vertex{
                           {X: 10.7, Y: 13.3, Z: 25.1},
                           {X: 18.3, Y: 16.9, Z: 16.4},
                      }
            }, 
}

The compiler would output such an error:

cannot use []Pixel literal (type []Pixel) as type []interface {} in field value

If I switch []interface{} to []Pixel, I can initialize the map but I can do it only with a unique type Pixel or Vertex.

Is there a way to force the compiler to accept array initialization with a specific struct while declaring it as an array of interface?

  • 写回答

4条回答 默认 最新

  • duanao4503 2018-09-03 13:04
    关注

    If you have to create a slice of values for passing to something that requires a slice of interface{} (which, depending on the context, may or may not be appropriate design) or a slice of any more specific interface, you have to specify each element fully, like this:

    []interface{}{ 
        Pixel{X: 12.5, Y: 23.4},
        Pixel{X: 17.2, Y: 7.9},
    }
    

    That also means that you can pass things like:

    []interface{}{
        Pixel{X: 12.5, Y: 23.4},
        Vertex{X: 10.7, Y: 13.3, Z: 25.1},
    }
    

    which is hardly something you intended, and compiler won't warn you. I don't see that a big deal for the testing code, though.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(3条)

报告相同问题?

悬赏问题

  • ¥15 MATLAB图像问题
  • ¥20 树莓派5做人脸情感识别与反馈系统
  • ¥15 selenium 控制 chrome-for-testing 在 Linux 环境下报错 SessionNotCreatedException
  • ¥15 使用pyodbc操作SQL数据库
  • ¥15 MATLAB实现下列
  • ¥30 mininet可视化打不开.mn文件
  • ¥50 C# 全屏打开Edge浏览器
  • ¥80 WEBPACK性能优化
  • ¥30 python拟合回归分析
  • ¥500 metaswitch 6010