> For the complete documentation index, see [llms.txt](https://docs.hex-rays.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hex-rays.com/9.0/developer-guide/idc/idc-api-reference/alphabetical-list-of-idc-functions/393.md).

# add\_struc

```
define a new structure type
     index    - Not used anymore
     name     - name of the new structure type.
     is_union - 0: structure
                1: union

returns: -1 if can't define structure type because of bad structure name:
            the name is ill-formed or is already used in the program.
         otherwise returns ID of the new structure type

long add_struc(long index, string name, long is_union);
```


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