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| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version

## *pass-structs-by-value*

Determines how the foreign interface will respond to a structure passed into def-foreign-call as an argument, or returned from the same in the returning keyword argument. This variable also affects the behavior of defun-foreign-callable. The argument or return value can be specified C style as by value (without a *) or by reference (with a *).

See Passing structures by value in foreign-functions.htm for more information.

This variable can have the following values:

- `nil` - structs passed by value are converted to pass-by-reference when seen, silently, as was the old behavior.
- `:warn` - structs passed by value are converted to pass-by-reference when seen, and in addition a warning is issued. This is the default value.
- `t` - structs specified as passed by value are actually passed by value, making the interface consistent with C calling conventions.

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page was not revised from the 10.0 page.
Created 2019.8.20.

|  | ToC | DocOverview | CGDoc | RelNotes | FAQ | Index | PermutedIndex
| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version