dictionary - Can not assign to pair in a map

Question

I have the following pair defined in my go program

type pair struct {
  a float64
  b float64
}

Then I create a map:

dictionary map[string]pair

I first add one element:

dictionary["xxoo"] = pair{5.0, 2.0}

Then I am trying to do this:

dictionary["xxoo"].b = 5.0  // try to change from 2.0 to 5.0

The last line doesn't compile and it said "can not assign to it"

I want to know what's the reason for this?

Answer 1

Waitting for answers