add_of(3)

💖 add_of(3) — the little overflow-checker that could 💖

okay bestie, gather round, because today we're talking about add_of, a function from the Library Functions Manual and honestly? she's doing the most for you and you don't even know it yet.

✨ NAME ✨

add_of — add two integers, and check for arithmetic overflow 🫶

like. she adds. she checks. she's an icon.

🌸 SYNTAX 🌸

#include <libowfat/rangecheck.h>

int add_of(dest,a,b);

that's it, that's the whole vibe. include the header, call the macro, live your truth. ✨

🦋 DESCRIPTION 🦋

so here's the tea ☕: if calculating a+b is possible without causing undefined behavior or an arithmetic overflow in C, and the sum actually fits into the destination integer type? she does dest=a+b and returns 0. slay. no cap.

otherwise? she returns 1. that's it. that's the whole girl. 💅

🎀 Note, bestie: this is a macro, so dest does not have to be a pointer. yeah. you heard me. iconic behavior honestly.

🙈 BUGS 🙈

okay so this is the part where things get a lil chaotic and we need to talk about it 😭

in the multiplication functions, a return value of 1 signals success and 0 signals failure.

but in add_of, sub_of and assign? it's the other way around. 💀

so like. read the return value carefully. do not get got. i'm begging you. 🫶

💜 SEE ALSO 💜

• sub_of(3)
• assign(3)
• imult16(3)
• umult16(3)
• imult32(3)
• umult32(3)
• imult64(3)
• umult64(3)

go read them too, they're all part of the same friendship group ✨

and that's the whole page, bestie 🎀 shoutout to the Library Functions Manual for hosting her, and shoutout to add_of(3) herself for being the responsible one who checks before she sums. stay safe out there and always check your overflow, ily 💖🦋🌸