# What are the true portable or best to define real 4 real 8 integer 4 integer 8, etc?

**URL:** <https://fortran-lang.discourse.group/t/what-are-the-true-portable-or-best-to-define-real-4-real-8-integer-4-integer-8-etc/3197>\
**Category:** Uncategorized\
**Created:** [April 9, 2022, 6:27pm UTC](https://fortran-lang.discourse.group/t/what-are-the-true-portable-or-best-to-define-real-4-real-8-integer-4-integer-8-etc/3197 "2022-04-09T18:27:44Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![Beliavsky](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@Beliavsky](https://fortran-lang.discourse.group/u/Beliavsky)\
**Post date:** [April 10, 2022, 1:11am UTC](https://fortran-lang.discourse.group/t/what-are-the-true-portable-or-best-to-define-real-4-real-8-integer-4-integer-8-etc/3197/6 "2022-04-10T01:11:57Z")

</div>

> [@FortranFan](#):
>
> There is no need really to reinvent the wheel on this matter anymore, you should consider simply using
> 
> ```fortran
> use stdlib_kinds ..
> 
> ```

Depending on the options chosen, that file could be

```auto
module stdlib_kinds
  use iso_fortran_env, only: int8, int16, int32, int64
  use iso_c_binding, only: c_bool
  implicit none
  private
  public :: sp, dp, xdp, qp, int8, int16, int32, int64, lk, c_bool

  !> Single precision real numbers
  integer, parameter :: sp = selected_real_kind(6)

  !> Double precision real numbers
  integer, parameter :: dp = selected_real_kind(15)

  !> Extended double precision real numbers
  integer, parameter :: xdp = selected_real_kind(18)

  !> Quadruple precision real numbers
  integer, parameter :: qp = selected_real_kind(33)

  !> Default logical kind parameter
  integer, parameter :: lk = kind(.true.)

end module stdlib_kinds

```

With the driver

```auto
program main
use iso_fortran_env, only: compiler_version
use stdlib_kinds
implicit none
print*,trim(compiler_version())
print "(*(a6))","sp","dp","xdp","qp","lk"
print "(*(i6))",sp,dp,xdp,qp,lk
end program main

```

sample output is

```auto
 GCC version 12.0.1 20220213 (experimental)
    sp dp xdp qp lk
     4 8 10 16 4

```

```auto
 Intel(R) Fortran Intel(R) 64 Compiler Classic for applications running on Intel
 (R) 64, Version 2021.5.0 Build 20211109_000000
    sp dp xdp qp lk
     4 8 16 16 4

```

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