在这里我们将看到C 或 C++中nextafter()和nextforward()函数的效果。这些函数存在于math.h或 cmath 库中。
如果函数类似于nextafter(a, b)和nextforward(a, b)。这些函数用于在 b 的方向上找到 a 之后的下一个可表示值。的nextforward()具有更精确的第二参数b。
#include <stdio.h>
#include <math.h>
main () {
//nextafter 函数()
printf ("Smallest representable number after 0 towards 1 : %e\n", nextafter(0.0, 1.0));
printf ("Largest representable number before -1 towards 0 :%e\n", nextafter(0.0, -1.0));
printf ("Largest +ve representable number after 0.8 : %e\n", nextafter(0.8, 0.0));
// 使用 nexttoward
printf("\n");
printf ("Smallest representable number after 0 towards 1 : %e\n", nexttoward(0.0, 1.0));
printf ("Largest representable number before -1 towards 0 : %e\n", nexttoward(0.0, -1.0));
printf ("Largest +ve representable number after 0.8 : %e\n", nexttoward(0.8, 0.0));
}输出结果Smallest representable number after 0 towards 1 : 4.940656e-324 Largest representable number before -1 towards 0 :-4.940656e-324 Largest +ve representable number after 0.8 : 8.000000e-001 Smallest representable number after 0 towards 1 : 4.940656e-324 Largest representable number before -1 towards 0 : -4.940656e-324 Largest +ve representable number after 0.8 : 8.000000e-001