3 ms·You don't have to go that far.. Oracle Studio (nee Sun Studio) for Solaris doesn't support it.by apaprocki 10y agoYou don't have to go that far.. Oracle Studio (nee Sun Studio) for Solaris doesn't support it.loeg 10y agoIsn't that more niche than embedded toolchains?slavik81 10y agoWikipedia lists it as supported since version 12.5. https://en.wikipedia.org/wiki/Pragma_once#Portability https://en.wikipedia.org/wiki/Pragma_once#Portability