# CMP0007

list command no longer ignores empty elements.

This policy determines whether the list command will ignore empty elements in the list. CMake 2.4 and below list commands ignored all empty elements in the list. For example, `a;b;;c` would have length 3 and not 4. The `OLD` behavior for this policy is to ignore empty list elements. The `NEW` behavior for this policy is to correctly count empty elements in a list.

This policy was introduced in CMake version 2.6.0. CMake version 3.17.2 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.