golang nextafter 代码
文件路径：/src/math/nextafter.go
/ Copyright 2010 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
package math
/ Nextafter32 returns the next representable float32 value after x towards y.
/
/ Special cases are:
/
/ Nextafter32(x, x) = x
/ Nextafter32(NaN, y) = NaN
/ Nextafter32(x, NaN) = NaN
func Nextafter32(x, y float32) (r float32) {
switch {
case IsNaN(float64(x)) || IsNaN(float64(y)): / special case
r = float32(NaN())
case x == y:
r = x
case x == 0:
r = float32(Copysign(float64(Float32frombits(1)), float64(y)))
case (y > x) == (x > 0):
r = Float32frombits(Float32bits(x) + 1)
default:
r = Float32frombits(Float32bits(x) - 1)
}
return
}
/ Nextafter returns the next representable float64 value after x towards y.
/
/ Special cases are:
/
/ Nextafter(x, x) = x
/ Nextafter(NaN, y) = NaN
/ Nextafter(x, NaN) = NaN
func Nextafter(x, y float64) (r float64) {
switch {
case IsNaN(x) || IsNaN(y): / special case
r = NaN()
case x == y:
r = x
case x == 0:
r = Copysign(Float64frombits(1), y)
case (y > x) == (x > 0):
r = Float64frombits(Float64bits(x) + 1)
default:
r = Float64frombits(Float64bits(x) - 1)
}
return
}