STDC_COUNT_ZEROS(3)

✨ STDC_COUNT_ZEROS(3) ✨

okay so this is the STDC_COUNT_ZEROS(3) page, and it lives in the Library Functions Manual. it's giving niche-bit-math main character energy, and honestly? we're here for it. 💅✨

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🌸 NAME 🌸

stdc_count_zeros — count the zeros in an integer. no cap, that's the whole name vibe. 💖

🦋 SYNOPSIS 🦋

okay bestie, here's the exact synopsis — do not let the _uc / _us / _ui / _ul / _ull alphabet soup scare you. iykyk. 🫶

Standard C Library (libc, -lc) #include <stdbit.h>

unsigned int
stdc_count_zeros_uc(unsigned char value);

unsigned int
stdc_count_zeros_us(unsigned short value);

unsigned int
stdc_count_zeros_ui(unsigned int value);

unsigned int
stdc_count_zeros_ul(unsigned long value);

unsigned int
stdc_count_zeros_ull(unsigned long long value);

unsigned int
stdc_count_zeros(value);

🎀 DESCRIPTION 🎀

The stdc_count_zeros_type() family of functions returns the number of bits set to 0 in value, where value is of type unsigned char, unsigned short, unsigned int, unsigned long, or unsigned long long for type being uc, us, ui, ul, or ull respectively. 💖

This is also known as the “population count” (popcount) or “Hamming weight” of the complement of value. yes, we're counting the zero bits and calling it fancy. ✨

The stdc_count_zeros(value) type-generic macro picks the appropriate stdc_count_zeros_type() function based on the type of value. the way it just knows? obsessed. 🫶

🌈 RETURN VALUES 🌈

Returns the number of bits set to 0 in value. fr fr, that's the whole return value. highkey perfect. 💅

👑 SEE ALSO 👑

• stdbit(3) 🦋
• stdc_count_ones(3) 🦋

💜 STANDARDS 💜

The stdc_count_zeros_type() family of functions and the stdc_count_zeros() type-generic macro conform to . 🎀

standards vibe check: yes, it literally ends with conform to . — that lonely period is canon, bestie. 💀

🦋 HISTORY 🦋

The stdc_count_zeros_type() family of functions and the stdc_count_zeros() type-generic macro were added in FreeBSD 15.1. slay. 👑

🌟 AUTHOR 🌟

Robert Clausecker <fuz@FreeBSD.org> — thank you for this zero-counting gift, legend. 🫶

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xoxo bestie, this was STDC_COUNT_ZEROS(3) — brought to you by Debian and dated November 9, 2025. now go count some zeros, periodt. 💖💅✨