# CMP0085

`$<IN_LIST:...>` handles empty list items.

In CMake 3.13 and lower, the `$<IN_LIST:...>` generator expression always returned `0` if the first argument was empty, even if the list contained an empty item. This behavior is inconsistent with the `IN_LIST` behavior of `if()`, which this generator expression is meant to emulate. CMake 3.14 and later handles this case correctly.

The `OLD` behavior of this policy is for `$<IN_LIST:...>` to always return `0` if the first argument is empty. The `NEW` behavior is to return `1` if the first argument is empty and the list contains an empty item.

This policy was introduced in CMake version 3.14. CMake version 3.16.3 warns when the policy is not set and uses `OLD` behavior. Use the `cmake_policy()` command to set it to `OLD` or `NEW` explicitly.

Note

The `OLD` behavior of a policy is `deprecated by definition` and may be removed in a future version of CMake.