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Function std.math.nextafter

Calculates the next representable value after x in the direction of y.

T nextafter(T) (
  const T x,
  const T y
) pure nothrow @nogc @safe;

If y > x, the result will be the next largest floating-point value; if y < x, the result will be the next smallest value. If x == y, the result is y.

Remarks

This function is not generally very useful; it's almost always better to use the faster functions nextUp() or nextDown() instead.

The FE_INEXACT and FE_OVERFLOW exceptions will be raised if x is finite and the function result is infinite. The FE_INEXACT and FE_UNDERFLOW exceptions will be raised if the function value is subnormal, and x is not equal to y.

Example

float a = 1;
assert(is(typeof(nextafter(a, a)) == float));
assert(nextafter(a, a.infinity) > a);

double b = 2;
assert(is(typeof(nextafter(b, b)) == double));
assert(nextafter(b, b.infinity) > b);

real c = 3;
assert(is(typeof(nextafter(c, c)) == real));
assert(nextafter(c, c.infinity) > c);
}

//real nexttoward(real x, real y) { return core.stdc.math.nexttowardl(x, y); 

Authors

Walter Bright, Don Clugston, Conversion of CEPHES math library to D by Iain Buclaw and David Nadlinger

License

Boost License 1.0.