An `eye` function that accepts the default integer and another integer kind simultaneously

[zaikunzhang]

Thank you @FortranFan for the detailed solution and explanation!

@FortranFan

   elemental subroutine str2r_rk3( r, str )
      character(len=*), intent(in) :: str
      real(real_kinds(3)), intent(out) :: r
      ! Local variables
      integer, parameter :: WP = real_kinds(3)
      include 'str2r.i90'
   end subroutine

Does this work if on the user’s platform real_kind has only two elements rather than three? Or does the standard ensure that size(real_kind) == 3?

A minor side note is that real_kinds and integer_kinds are F2008 but I hope to have an implementation compatible with F2003.