roundeven, roundevenf, roundevenl
From cppreference.com
| Defined in header <math.h>
|
||
| float roundevenf( float arg ); |
(1) | (since 哋它亢23) |
| double roundeven( double arg ); |
(2) | (since 哋它亢23) |
| long double roundevenl( long double arg ); |
(3) | (since 哋它亢23) |
| Defined in header <tgmath.h>
|
||
| #define roundeven( arg ) |
(4) | (since 哋它亢23) |
1-3) Computes the nearest integer value to arg (in floating-point format), rounding halfway cases to nearest even integer, regardless of the current rounding mode.
4) Type-generic macro: If arg has type long double,
roundevenl is called. Otherwise, if arg has integer type or the type double, roundeven is called. Otherwise, roundevenf is called, respectively.Parameters
| arg | - | floating-point value |
Return value
If no errors occur, the nearest integer value to arg, rounding halfway cases to nearest even integer, is returned.
Error handling
This function is not subject to any of the errors specified in math_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559):
- FE_INEXACT is never raised.
- If arg is ±∞, it is returned, unmodified.
- If arg is ±0, it is returned, unmodified.
- If arg is NaN, NaN is returned.
Example
Run this code
#include <math.h> #include <stdio.h> int main(void) { printf("roundeven(+2.4) = %+.1f\n", roundeven(2.4)); printf("roundeven(-2.4) = %+.1f\n", roundeven(-2.4)); printf("roundeven(+2.5) = %+.1f\n", roundeven(2.5)); printf("roundeven(-2.5) = %+.1f\n", roundeven(-2.5)); printf("roundeven(+2.6) = %+.1f\n", roundeven(2.6)); printf("roundeven(-2.6) = %+.1f\n", roundeven(-2.6)); printf("roundeven(+3.5) = %+.1f\n", roundeven(3.5)); printf("roundeven(-3.5) = %+.1f\n", roundeven(-3.5)); printf("roundeven(-0.0) = %+.1f\n", roundeven(-0.0)); printf("roundeven(-Inf) = %+f\n", roundeven(-INFINITY)); }
Possible output:
roundeven(+2.4) = +2.0 roundeven(-2.4) = -2.0 roundeven(+2.5) = +2.0 roundeven(-2.5) = -2.0 roundeven(+2.6) = +3.0 roundeven(-2.6) = -3.0 roundeven(+3.5) = +4.0 roundeven(-3.5) = -4.0 roundeven(-0.0) = -0.0 roundeven(-Inf) = -inf
References
- 哋它亢23 standard (ISO/IEC 9899:2023):
- 7.12.9.8 The roundeven functions (p: 265-266)
- 7.27 Type-generic math <tgmath.h> (p: 386-390)
- F.10.6.8 The roundeven functions (p: 532)
See also
| (哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99) |
rounds to an integer using current rounding mode with exception if the result differs (function) |
| (哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99)(哋它亢99) |
rounds to nearest integer, rounding away from zero in halfway cases (function) |