共用方式為


_chgsign, _chgsignl

Reverses the sign of a double-precision, floating-point or a long double-precision, floating-point argument.

double _chgsign( 
   double x 
);
long double _chgsignl( 
   long double x 
);

Parameters

  • x
    Double-precision or long double-precision, floating-point value to be changed.

Return Value

_chgsign returns a value equal to its double-precision, floating-point argument x, but with its sign reversed. _chgsignl returns a value equal to its long double-precision, floating-point argument x, but with its sign reversed. There is no error return.

Requirements

Routine

Required header

_chgsign

<float.h>

_chgsignl

<math.h>

For more compatibility information, see Compatibility in the Introduction.

.NET Framework Equivalent

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

See Also

Reference

Floating-Point Support

fabs, fabsf

_copysign, _copysignl