double remquo(double x,double y,int *quo);
float remquof(float x,float y,int *quo);
long double remquol(long double x,long double y,int *quo);

The remquo functions compute the same remainder as the remainder functions. In
the object pointed to by quo they store a value whose sign is the sign of x/y and whose
magnitude is congruent modulo 2^n
to the magnitude of the integral quotient of x/y,where
n is an implementation-defined integer greater than or equal to 3.

The remquo functions return x REM y. If y is zero,the value stored in the object
pointed to by quo is unspecified and whether a domain error occurs or the functions
return zero is implementation defined.

我理解它返回的内容,它返回fmod(x,y),但我不理解整个部分.它在语义上是否与此相同？

*quo = (int) x/y;
*quo %= n; /* n implementation defined */

我的最后一个问题是,这个功能有用吗？