Defined in header <math.h> | ||
---|---|---|
float roundevenf( float arg ); | (1) | (since C23) |
double roundeven( double arg ); | (2) | (since C23) |
long double roundevenl( long double arg ); | (3) | (since C23) |
Defined in header <tgmath.h> | ||
#define roundeven( arg ) | (4) | (since C23) |
arg
(in floating-point format), rounding halfway cases to nearest even integer, regardless of the current rounding mode.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.arg | - | floating point value |
If no errors occur, the nearest integer value to arg
, rounding halfway cases to nearest even integer, is returned.
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 arg
is ±∞, it is returned, unmodified arg
is ±0, it is returned, unmodified arg
is NaN, NaN is returned #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
(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99) | rounds to an integer using current rounding mode with exception if the result differs (function) |
(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99) | rounds to nearest integer, rounding away from zero in halfway cases (function) |
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