>you have a model with 20 fields and need to create a tiny slice of it (with let's say three fields), you need a few lines of boilerplate: create a record with those fields (1-3 LOC):

>create a mapper for it:

> ...

>Go developers usually "don't need these complications", so this is just another self-inflicted problem.

In Go:

  type DTO struct {
    A, B, C string
  }

  // copy the fields to the DTO
  return DTO{A: o.A, B: o.B, C: o.C}