Hi everyone, i'm a beginner in c, i'm actually recoding printf and i'm trying to understand how do va_arg, va_start, va_end work, i read the stdarg.h but i couldn't get it

00006 #ifndef STDARG_H

00007 #define STDARG_H

00009typedefchar *va_list;

00011#define va_rounded_size(type) \

00012 (((sizeof (type) + sizeof (int) - 1) / sizeof (int)) * sizeof (int))

00014#define va_start(ap, v) \

00015 ((void) (ap = (va_list) &v + va_rounded_size (v)))

00016

00017#define va_arg(ap, type) \

00018 (ap += va_rounded_size (type), *((type *)(ap - va_rounded_size (type))))

00019

00020#define va_end(ap) ((void) (ap = 0))

00021

00022 #endif

i would be thankful if someone explained it to me

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Edité par ZakariaElBaghazaoui 13 décembre 2019 à 12:36:31