ROUND(3P)

💖 PROLOG 💖

okay so before we even get into it — this manual page is part of the POSIX Programmer's Manual, bestie. and like, the Linux implementation of this interface may differ (so pls consult the corresponding Linux manual page for the deets on Linux behavior, fr), or honestly the interface may not even be implemented on Linux at all. 🙈

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✨ NAME ✨

round, roundf, roundl — round to the nearest integer value in a floating-point format 🎀

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🌸 SYNOPSIS 🌸

#include <math.h>

double round(double x);
float roundf(float x);
long double roundl(long double x);

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🦋 DESCRIPTION 🦋

The functionality described on this reference page is aligned with the ISO C standard. Like, if there's any conflict between the requirements described here and the ISO C standard, that conflict is unintentional — no drama intended, periodt. This volume of POSIX.1‐2017 defers to the ISO C standard. 💅

These functions shall round their argument to the nearest integer value in floating-point format, rounding halfway cases away from zero, regardless of the current rounding direction. so it does NOT care what direction you're rounding in, it's got main character energy and does its own thing. 🔥

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⭐ RETURN VALUE ⭐

Upon successful completion, these functions shall return the rounded integer value. the result shall have the same sign as x. 💖

• If x is NaN, a NaN shall be returned.
• If x is ±0 or ±Inf, x shall be returned.

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💀 ERRORS 💀

No errors are defined. nope, not a single one. iconic behavior honestly.

The following sections are informative.

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🌈 EXAMPLES 🌈

None. (yeah i know, we were all hoping for a little demo moment 😭)

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💜 APPLICATION USAGE 💜

okay this part is important so listen up:

The integral value returned by these functions need not be expressible as an intmax_t. The return value should be tested before assigning it to an integer type to avoid the undefined results of an integer overflow. like, pls check before you yeet it into an integer type, bestie. 🙈

These functions may raise the inexact floating-point exception if the result differs in value from the argument. 👑

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🎀 RATIONALE 🎀

None.

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🧚 FUTURE DIRECTIONS 🧚

None.

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🔥 SEE ALSO 🔥

• feclearexcept()
• fetestexcept()

The Base Definitions volume of POSIX.1‐2017, Section 4.20, Treatment of Error Conditions for Mathematical Functions, <math.h>

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💅 COPYRIGHT 💅

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

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and that's the whole page, bestie!! 🫶 this one came to you from IEEE/The Open Group, dated 2017, and it lives in the POSIX Programmer's Manual as ROUND(3P) — go round some numbers, you got this, mwah 💖✨