type Foo struct {
    ID int
}

type Bar struct {
    ID int
}

func convertAtoB(a A) *B {
    return &B{a.ID}
}

func (a* A) convertToB() *B {
    return &B{a.ID}
}

type Name Struct {
  ...
  funcSlot interface{}
  ...
}

func (n *Name) FuncName() error {
  return nil
}

func NewName() (n *Name) {
  ...
  n.funcSlot = (*Name).FuncName
  ...
}

type NAME interface {
  ...
  FuncName() error
  ...
}