objective c - C printf Format Specifier %_fi -

objective c - C printf Format Specifier %_fi -

does know if underscore format specifier (like %_f) in c code? i+ve found code in book uses it, i've googled , found nothing. i've tested next objective-c code in xcode , xcode seems not back upwards specifier. valid in c?

-(void) print { printf( "%_f + %_fi", real, imaginary ); }

thanks!

the os x man page printf() says this:

an optional separator character ( , | ; | : | _ ) used separating multiple values when printing altivec or sse vector, or other multi-value unit.

note: extension printf() specification. behaviour of these values printf() defined operating systems conforming altivec technology programming interface manual. (at time of writing includes mac os x 10.2 , later.)

objective-c c printf specifier