# ArgumentEncoder Error

**URL:** <https://forum.dfinity.org/t/argumentencoder-error/39180>\
**Category:** Language Support\
**Created:** [December 21, 2024, 9:18am UTC](https://forum.dfinity.org/t/argumentencoder-error/39180 "2024-12-21T09:18:15Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ydr990318](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/ydr990318/32/17541_2.png) [@ydr990318](https://forum.dfinity.org/u/ydr990318)\
**Post date:** [December 21, 2024, 9:18am UTC](https://forum.dfinity.org/t/argumentencoder-error/39180/1 "2024-12-21T09:18:15Z")

</div>

Hey guys, here’s a problem, I’m trying to implement cross-canister calls using rust’s pub-sub pattern, but this line of code keeps having problems:

> let return\_result:Result\<Vec, (ic\_cdk::api::call::RejectionCode, String)\> = ic\_cdk:. call(publisher\_id, “create\_tensor\_and\_run\_model”, (max\_tokens,token\_ids)).await;

Error message reported as:

> the trait bound `for<'a> std::vec::Vec<i64>. ArgumentDecoder<'a>` is not satisfied  
> the following other types implement trait `ArgumentDecoder<'a>`.  
> ()  
> (A, B)  
> (A, B, C)  
> (A, B, C, D)  
> (A, B, C, D, E)  
> (A, B, C, D, E, F)  
> (a, b, c, d, e, f, g)  
> (A, B, C, D, E, F, G, H)  
> and 9 othersrustcClick for full compiler diagnostic  
> call.rs(389, 36): required by a bound in `ic_cdk::call`

where max\_tokens is of type u8 and token\_ids is of type Vec \<i64 .