将切片解包到结构值

Question

Let's say that you have this struct,

type Color struct {
    R uint8
    G uint8
    B uint8
    A uint8
}

And this slice,

s := []uint8{50, 60, 100, 100}

Is there a way to "unpack" the slice to the struct? (Like with a spread operator or something)

c := Color{s...}

Instead of this I mean,

c := Color{s[0], s[1], s[2], s[3]}

Answer 1

Unfortunately there is no way to do this. In case you want to reduce your writing work, there could be a workaround:

func NewColor(values ...uint8) Color {
   return Color {
    R: values [0], G: values [1], B: values [2], A: values [3],
   }
}

However this is dangerous unless you also add checks for out-of-bounds. You could add something like this to prevent it, however it might leave you with a wrong color then:

if len(values) != 4 { 
   return Color {} 
}

You can then just create the color with the way you wanted:

s := []uint8{50, 60, 100, 100}
color := NewColor(s...)

Hope that helps you.