A preview feature may be defined completely in header files or it may require some additional support defined in a library.
For a preview feature that is contained completely in header files, a feature-specific macro must be defined before inclusion of the header files.
#define TBB_PREVIEW_FOO 1 #include "tbb/foo.h"
If a preview feature requires support from a library, then an additional library must be linked with the application.
The use of separate headers, feature-specific macros and separate libraries mitigates the impact of preview features on other product features.
Unless a preview feature is explicitly enabled using the above mechanisms, it will have no impact on the application.