# How to create value of type stamped\_t (a, x)?
**URL:** https://discourse.ats-lang.org/t/how-to-create-value-of-type-stamped-t-a-x/162
**Category:** Google Group
**Created:** [June 18, 2015, 1:18pm UTC](https://discourse.ats-lang.org/t/how-to-create-value-of-type-stamped-t-a-x/162 "2015-06-18T13:18:45Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@gmhwxi](https://discourse.ats-lang.org/u/gmhwxi)
#### Post date: [June 18, 2015, 1:18pm UTC](https://discourse.ats-lang.org/t/how-to-create-value-of-type-stamped-t-a-x/162/1 "2015-06-18T13:18:45Z")
Yes, you need a cast.On Thu, Jun 18, 2015 at 8:54 AM, Kiwamu Okabe [kiw...@debian.or.jp](mailto:kiw...@debian.or.jp) wrote:
> Hi all,
>
> Today I read interfaces of libats/SATS/gfarray.sats.
>
> fun{a:t@ype}
> gfarray\_set\_at
> {l:addr}
> {x:int}{xs1:ilist}{xs2:ilist}
> {i:int}
> (
> pf1: UPDATE (x, xs1, i, xs2)
> , pf2: !gfarray\_v (a, l, xs1) \>\> gfarray\_v (a, l, xs2)
> | p: ptr l, i: size\_t i, x: stamped\_t (a, x)
> ) :\ void // end of [gfarray\_set\_at]
>
> The gfarray\_set\_at function need stamped\_t (a, x) type to change
> entity of the array.
>
> How to create value of type stamped\_t (a, x)?
> Need to cast for it?
>
> ## Best regards,
>
> Kiwamu Okabe at METASEPI DESIGN
>
> –
> You received this message because you are subscribed to the Google Groups
> “ats-lang-users” group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [ats-lang-user...@googlegroups.com](mailto:ats-lang-user...@googlegroups.com).
> To post to this group, send email to [ats-lan...@googlegroups.com](mailto:ats-lan...@googlegroups.com).
> Visit this group at [http://groups.google.com/group/ats-lang-users](http://groups.google.com/group/ats-lang-users).
> To view this discussion on the web visit
> [https://groups.google.com/d/msgid/ats-lang-users/CAEvX6dkpUOnweJWKn1SQ7B0qpOJsWos3r\_8OCT1%2B\_Q6RzsuLnA%40mail.gmail.com](https://groups.google.com/d/msgid/ats-lang-users/CAEvX6dkpUOnweJWKn1SQ7B0qpOJsWos3r_8OCT1%2B_Q6RzsuLnA%40mail.gmail.com)
> .
---
### Author:  [@gmhwxi](https://discourse.ats-lang.org/u/gmhwxi)
#### Post date: [June 19, 2015, 3:34am UTC](https://discourse.ats-lang.org/t/how-to-create-value-of-type-stamped-t-a-x/162/2 "2015-06-19T03:34:37Z")
Done.
castfn stamp\_t : {a:t@ype} (a) → [x:int] stamped\_t(a, x)
castfn stamp\_vt : {a:vt@ype} (a) → [x:int] stamped\_vt(a, x)On Thursday, June 18, 2015 at 10:42:08 PM UTC-4, Kiwamu Okabe wrote:
> On Fri, Jun 19, 2015 at 8:06 AM, Hongwei Xi \<[gmh...@gmail.com](mailto:gmh...@gmail.com) \\> wrote:
>
> > The following function is a _safe_ cast:
> >
> > {a:t@ype} (a) → [x:int] stamped\_t(a, x)
>
> ## Use castfn? How about define the function at prelude/basics\_dyn.sats?
>
> Kiwamu Okabe at METASEPI DESIGN
---
### Author:  [@gmhwxi](https://discourse.ats-lang.org/u/gmhwxi)
#### Post date: [June 18, 2015, 11:06pm UTC](https://discourse.ats-lang.org/t/how-to-create-value-of-type-stamped-t-a-x/162/3 "2015-06-18T23:06:45Z")
The following function is a _safe_ cast:
{a:t@ype} (a) → [x:int] stamped\_t(a, x)On Thu, Jun 18, 2015 at 9:18 AM, Hongwei Xi [gmh...@gmail.com](mailto:gmh...@gmail.com) wrote:
> Yes, you need a cast.
>
> On Thu, Jun 18, 2015 at 8:54 AM, Kiwamu Okabe [kiw...@debian.or.jp](mailto:kiw...@debian.or.jp) wrote:
>
> > Hi all,
> >
> > Today I read interfaces of libats/SATS/gfarray.sats.
> >
> > fun{a:t@ype}
> > gfarray\_set\_at
> > {l:addr}
> > {x:int}{xs1:ilist}{xs2:ilist}
> > {i:int}
> > (
> > pf1: UPDATE (x, xs1, i, xs2)
> > , pf2: !gfarray\_v (a, l, xs1) \>\> gfarray\_v (a, l, xs2)
> > | p: ptr l, i: size\_t i, x: stamped\_t (a, x)
> > ) :\ void // end of [gfarray\_set\_at]
> >
> > The gfarray\_set\_at function need stamped\_t (a, x) type to change
> > entity of the array.
> >
> > How to create value of type stamped\_t (a, x)?
> > Need to cast for it?
> >
> > ## Best regards,
> >
> > Kiwamu Okabe at METASEPI DESIGN
> >
> > –
> > You received this message because you are subscribed to the Google Groups
> > “ats-lang-users” group.
> > To unsubscribe from this group and stop receiving emails from it, send an
> > email to [ats-lang-user...@googlegroups.com](mailto:ats-lang-user...@googlegroups.com).
> > To post to this group, send email to [ats-lan...@googlegroups.com](mailto:ats-lan...@googlegroups.com).
> > Visit this group at [http://groups.google.com/group/ats-lang-users](http://groups.google.com/group/ats-lang-users).
> > To view this discussion on the web visit
> > [https://groups.google.com/d/msgid/ats-lang-users/CAEvX6dkpUOnweJWKn1SQ7B0qpOJsWos3r\_8OCT1%2B\_Q6RzsuLnA%40mail.gmail.com](https://groups.google.com/d/msgid/ats-lang-users/CAEvX6dkpUOnweJWKn1SQ7B0qpOJsWos3r_8OCT1%2B_Q6RzsuLnA%40mail.gmail.com)
> > .