### warn_illunionmembers

Controls whether a warning is issued when illegal union members are made, such as unions with reference or non-trivial class members.

##### Syntax

#pragma warn_illunionmembers on | off | reset

##### Targets

All platforms.

##### Remarks

This pragma does not correspond to any panel setting. To check this setting, use __option (warn_illunionmembers), described in Checking Settings. The default setting is on.