## Function: SB-EXT:ADD-IMPLEMENTATION-PACKAGE
[![package](https://img.shields.io/badge/Package-SB--EXT-5f9ea0.svg?style=social&colorA=999999)](../) [![type](https://img.shields.io/badge/Type-Function-5f9ea0.svg?style=social&colorA=999999)](../#function) [![github](https://img.shields.io/badge/GitHub-View_the_source-5f9ea0.svg?style=social&colorA=999999&logo=github)](https://github.com/sbcl/sbcl/blob/master/src/code/target-package.lisp/) 

> Adds PACKAGES-TO-ADD as implementation packages of PACKAGE. Signals
> an error if PACKAGE or any of the PACKAGES-TO-ADD is not a valid
> package designator.

### Lambda list
```cl
(sb-impl::packages-to-add &optional package)
```