Controls whether or not to issue a warning message when #pragmaonceon is used in a precompiled header.
#pragma warn_pch_portability on | off | reset
If you enable this pragma, the compiler issues a warning message when you use #pragma once on in a precompiled header. This helps you avoid situations in which transferring a precompiled header from machine to machine causes the precompiled header to produce different results. For more information, see pragma once .
This pragma does not correspond to any panel setting. By default, this setting is off .