c++ - 除以余数时，奇数是否总是返回 floor？

Question

我能否确定 C++ 中的奇数在以存在余数的方式划分时应该始终返回结果的底数，或者是否有任何异常(exception)？我的意思是:

int x = 5;
x = x/2;
cout<<x;      //2

Answer 1

是的。你可以在 C++ 中确定这一点

ISO/IEC N3485(working draft)5.6.4中说

The binary / operator yields the quotient, and the binary % operator yields 
the remainder from the division of the first expression by the second.
   If the second  operand of / or % is zero the behavior is undefined. 
For integral operands the / operator yields the algebraic quotient with any 
fractional part discarded;81 if the quotient a/b is representable in the type 
of the result, (a/b)*b + a%b is equal to a; otherwise, the behavior of both 
a/b and a%b is undefined.