toString Function

   function toString(this) result(string)
      character(len=:), allocatable :: string
      class (GridCase), intent(in) :: this

      character(len=1) :: buf

      write(buf,'(i1)') this%nx
      string = '{nx:'//buf

      write(buf,'(i1)') this%ny
      string = string // ',ny:'//buf

      string = string // ',pole:'//this%pole
      string = string // ',dateline:'//this%dateline

      string = string // '}'

   end function toString