nextafter, nextafterf, nextafterl, _nextafter, _nextafterf, nexttoward, nexttowardf, nexttowardl
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Returns the next representable floating-point value.
Syntax
double nextafter(
double x,
double y
);
float nextafter(
float x,
float y
); /* C++ only, requires <cmath> */
long double nextafter(
long double x,
long double y
); /* C++ only, requires <cmath> */
float nextafterf(
float x,
float y
);
long double nextafterl(
long double x,
long double y
);
double _nextafter(
double x,
double y
);
float _nextafterf(
float x,
float y
); /* x64 only */
double nexttoward(
double x,
long double y
);
float nexttoward(
float x,
long double y
); /* C++ only, requires <cmath> */
long double nexttoward(
long double x,
long double y
); /* C++ only, requires <cmath> */
float nexttowardf(
float x,
long double y
);
long double nexttowardl(
long double x,
long double y
);
Parameters
x
The floating-point value to start from.
y
The floating-point value to go towards.
Return Value
Returns the next representable floating-point value of the return type after x in the direction of y. If x=y, the function returns y, converted to the return type, with no exception triggered. If x is not equal to y, and the result is a denormal or zero, the FE_UNDERFLOW and FE_INEXACT floating-point exception states are set, and the correct result is returned. If either x or y is a NAN, then the return value is one of the input NANs. If x is finite and the result is infinite or not representable in the type, a correctly signed infinity or NAN is returned, the FE_OVERFLOW and FE_INEXACT floating-point exception states are set, and errno is set to ERANGE.
Remarks
The nextafter and nexttoward function families are equivalent, except for the parameter type of y. If x and y are equal, the value returned is y converted to the return type.
Because C++ allows overloading, if you include <cmath> you can call overloads of nextafter and nexttoward that return float and long double types. In a C program, nextafter and nexttoward always return double.
The _nextafter and _nextafterf functions are Microsoft specific. The _nextafterf function is only available when compiling for x64.
Requirements
| Routine | Required header (C) | Required header (C++) |
|---|---|---|
nextafter, nextafterf, nextafterl, _nextafterf, nexttoward, nexttowardf, nexttowardl |
<math.h> | <math.h> or <cmath> |
_nextafter |
<float.h> | <float.h> or <cfloat> |
For more compatibility information, see Compatibility in the Introduction.