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.